Rename, clean up boards/variants (#21655)

* Consolidate variant scripts
* Rename Marlin-local boards
* Simplify variants where possible
* Rename variants
* CHITU_F103 and MEEB_3DP: Maple platform `platformio-build-stm32f1.py` uses the 'board' name, not 'board_build.variant' so folder names match 'board' and not `board_build.variant`.

ini/stm32f1.ini

@@ -65,7 +65,7 @@ monitor_speed     = 115200
 [env:STM32F103RC_meeb]
 platform          = ${common_stm32f1.platform}
 extends           = common_stm32f1
-board             = MEEB_3DP
+board             = marlin_MEEB_3DP
 build_flags       = ${common_stm32f1.build_flags}
                     -DDEBUG_LEVEL=0
                     -DSS_TIMER=4
@@ -114,8 +114,10 @@ upload_protocol   = serial
 [env:STM32F103RC_btt]
 platform          = ${common_stm32f1.platform}
 extends           = env:STM32F103RC
+board_build.address  = 0x08007000
+board_build.ldscript = STM32F103RC_SKR_MINI_256K.ld
 extra_scripts     = ${common_stm32f1.extra_scripts}
-  buildroot/share/PlatformIO/scripts/STM32F103RC_SKR_MINI.py
+  buildroot/share/PlatformIO/scripts/custom_board.py
 build_flags       = ${common_stm32f1.build_flags}
   -DDEBUG_LEVEL=0 -DSS_TIMER=4
 monitor_speed     = 115200
@@ -130,6 +132,7 @@ lib_deps          = ${env:STM32F103RC_btt.lib_deps}
 [env:STM32F103RC_btt_512K]
 platform          = ${common_stm32f1.platform}
 extends           = env:STM32F103RC_btt
+board_build.ldscript = STM32F103RC_SKR_MINI_512K.ld
 board_upload.maximum_size=524288
 build_flags       = ${env:STM32F103RC_btt.build_flags} -DSTM32_FLASH_SIZE=512
 
@@ -156,8 +159,10 @@ monitor_speed     = 115200
 [env:STM32F103RE_btt]
 platform          = ${common_stm32f1.platform}
 extends           = env:STM32F103RE
+board_build.address  = 0x08007000
+board_build.ldscript = STM32F103RE_SKR_E3_DIP.ld
 extra_scripts     = ${common_stm32f1.extra_scripts}
-  buildroot/share/PlatformIO/scripts/STM32F103RE_SKR_E3_DIP.py
+  buildroot/share/PlatformIO/scripts/custom_board.py
 build_flags       = ${common_stm32f1.build_flags} -DDEBUG_LEVEL=0 -DSS_TIMER=4
 debug_tool        = stlink
 upload_protocol   = stlink
@@ -190,7 +195,10 @@ upload_protocol = serial
 platform      = ${common_stm32f1.platform}
 extends       = common_stm32f1
 board         = genericSTM32F103VE
+board_build.address  = 0x08010000
+board_build.ldscript = STM32F103VE_longer.ld
 extra_scripts = ${common_stm32f1.extra_scripts}
+  buildroot/share/PlatformIO/scripts/custom_board.py
   buildroot/share/PlatformIO/scripts/STM32F103VE_longer.py
 build_flags   = ${common_stm32f1.build_flags}
   -DMCU_STM32F103VE -DSTM32F1xx -USERIAL_USB -DU20 -DTS_V12
@@ -330,7 +338,10 @@ extra_scripts = ${common_stm32f1.extra_scripts}
 platform      = ${common_stm32f1.platform}
 extends       = common_stm32f1
 board         = genericSTM32F103ZE
+board_build.address  = 0x0800A000
+board_build.ldscript = jgaurora_a5s_a1.ld
 extra_scripts = ${common_stm32f1.extra_scripts}
+  buildroot/share/PlatformIO/scripts/custom_board.py
   buildroot/share/PlatformIO/scripts/jgaurora_a5s_a1_with_bootloader.py
 build_flags   = ${common_stm32f1.build_flags}
   -DSTM32F1xx -DSTM32_XL_DENSITY
@@ -341,7 +352,7 @@ build_flags   = ${common_stm32f1.build_flags}
 [env:STM32F103CB_malyan]
 platform      = ${common_stm32f1.platform}
 extends       = common_stm32f1
-board         = malyanM200
+board         = marlin_malyanM200
 build_flags   = ${common_stm32f1.build_flags}
   -DMCU_STM32F103CB -D__STM32F1__=1 -std=c++1y -DSERIAL_USB -ffunction-sections -fdata-sections
   -Wl,--gc-sections -DDEBUG_LEVEL=0 -D__MARLIN_FIRMWARE__
@@ -354,7 +365,7 @@ lib_ignore    = ${common_stm32f1.lib_ignore}
 [env:chitu_f103]
 platform      = ${common_stm32f1.platform}
 extends       = common_stm32f1
-board         = CHITU_F103
+board         = marlin_CHITU_F103
 extra_scripts = pre:buildroot/share/PlatformIO/scripts/common-dependencies.py
   pre:buildroot/share/PlatformIO/scripts/STM32F1_create_variant.py
   buildroot/share/PlatformIO/scripts/chitu_crypt.py
@@ -379,9 +390,11 @@ build_flags   = ${env:chitu_f103.build_flags} -DCHITU_V5_Z_MIN_BUGFIX
 platform        = ${env:STM32F103RE.platform}
 extends         = env:STM32F103RE
 build_flags     = ${env:STM32F103RE.build_flags} -DTEMP_TIMER_CHAN=4
+board_build.address  = 0x08007000
+board_build.ldscript = creality.ld
 extra_scripts   = ${env:STM32F103RE.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/random-bin.py
-  buildroot/share/PlatformIO/scripts/STM32F103RET6_creality.py
+  buildroot/share/PlatformIO/scripts/custom_board.py
 debug_tool      = jlink
 upload_protocol = jlink