Split up platformio.ini (#21507)

ini/stm32f7.ini

@@ -0,0 +1,30 @@
+#
+# Marlin Firmware
+# PlatformIO Configuration File
+#
+
+#################################
+#                               #
+#     STM32F7 Architecture      #
+#                               #
+#################################
+
+#
+# ST NUCLEO-F767ZI Development Board
+# This environment is for testing purposes prior to control boards
+# being readily available based on STM32F7 MCUs
+#
+[env:NUCLEO_F767ZI]
+platform      = ${common_stm32.platform}
+extends       = common_stm32
+board         = nucleo_f767zi
+build_flags   = ${common_stm32.build_flags} -DTIMER_SERIAL=TIM9
+
+#
+# REMRAM_V1
+#
+[env:REMRAM_V1]
+platform      = ${common_stm32.platform}
+extends       = common_stm32
+board         = remram_v1
+build_flags   = ${common_stm32.build_flags}