add SPI path for include

Author: mean

Platform/Core/BoardFlags/CompilerFlagsSetterStm32.cmake

@@ -51,7 +51,8 @@ set(COMPILE_FLAGS "${COMPILE_FLAGS} ${STM32_SYSTEM_ROOT}/libmaple/include/libmap
 set(COMPILE_FLAGS "${COMPILE_FLAGS} ${STM32_SYSTEM_ROOT}/libmaple/usb/usb_lib/\" ") # Hack
 set(COMPILE_FLAGS "${COMPILE_FLAGS} ${STM32_SYSTEM_ROOT}/libmaple/usb/stm32f1/\" ") # Hack
 set(COMPILE_FLAGS "${COMPILE_FLAGS} ${STM32_SYSTEM_ROOT}/libmaple/stm32f1/include/\" ")
-
+set(COMPILE_FLAGS "${COMPILE_FLAGS} ${STM32_SYSTEM_ROOT}/../libraries/SPI/src/\" ")
+ 
 ADD_TO_COMPILE_FLAGS(build.vect   "")
 ADD_TO_COMPILE_FLAGS(menu.cpu.${ARDUINO_UPLOAD_METHOD}Method.build.vect  "")