Use a macro for HAL header redirection (#10380)

Marlin/src/HAL/platforms.h

@@ -0,0 +1,28 @@
+#ifndef _HAL_PLATFORMS_H_
+#define _HAL_PLATFORMS_H_
+
+#ifndef HAL_PLATFORM
+
+#ifdef __AVR__
+  #define HAL_PLATFORM HAL_AVR
+#elif defined(ARDUINO_ARCH_SAM)
+  #define HAL_PLATFORM HAL_DUE
+#elif defined(__MK64FX512__) || defined(__MK66FX1M0__)
+  #define HAL_PLATFORM HAL_TEENSY35_36
+#elif defined(TARGET_LPC1768)
+  #define HAL_PLATFORM HAL_LPC1768
+#elif defined(__STM32F1__) || defined(TARGET_STM32F1)
+  #define HAL_PLATFORM HAL_STM32F1
+#elif defined(STM32F7)
+  #define HAL_PLATFORM HAL_STM32F7
+#else
+  #error "Unsupported Platform!"
+#endif
+
+#endif // HAL_PLATFORM
+
+#define XSTR_(M) #M
+#define XSTR(M) XSTR_(M)
+#define HAL_PATH(PATH, NAME) XSTR(PATH/HAL_PLATFORM/NAME)
+
+#endif // _HAL_PLATFORMS_H_