HAL include and other adjustments (#14525)

Marlin/src/inc/MarlinConfig.h

@@ -27,16 +27,12 @@
 
 #include "MarlinConfigPre.h"
 
-#include HAL_PATH(../HAL, HAL.h)
+#include "../HAL/HAL.h"
 
 #include "../pins/pins.h"
 
 #include HAL_PATH(../HAL, spi_pins.h)
 
-#if defined(__AVR__) && !defined(USBCON)
-  #define HardwareSerial_h // trick to disable the standard HWserial
-#endif
-
 #include "Conditionals_post.h"
 #include "SanityCheck.h"
 
@@ -47,4 +43,3 @@
 #include "../core/language.h"
 #include "../core/utility.h"
 #include "../core/serial.h"
-#include "../core/minmax.h"

Marlin/src/inc/MarlinConfigPre.h

@@ -27,7 +27,6 @@
 // Prefix header to acquire configurations
 //
 
-#include "../HAL/platforms.h"
 #include "../core/boards.h"
 #include "../core/macros.h"
 #include "../core/millis_t.h"