Guard STM peripheral files

[BlakeFreer]

The stm mcal files rely on files which are generated per-project by CubeMX. Thus if a project does not use a peripheral (say ADC), then the mcal/stm/periph/adc.hpp file will have a ton of errors since the file does not exist.

We can use #ifdef guards to detect if the current project uses each peripheral and enable / disable the whole file accordingly. CubeMX generates an stm32f7xx_hal.h file which includes ...hal_conf.h which has #define statements to indicate which peripherals are enabled.

For an example, see mcal/stm32f767/periph/can.hpp and can.cc in the dev/can branch. https://github.com/macformula/racecar/blob/dev/can/firmware/mcal/stm32f767/periph/can.hpp

//// can.hpp ////
#include "stm32f7xx_hal.h"
#ifdef HAL_CAN_MODULE_ENABLED // this disables the code if #define HAL_CAN is commented out below


//// stm32f7xx_hal.h ////
#include "stm32f7xx_hal_conf.h"


//// stm32f7xx_hal_conf.h ////
/* #define HAL_CRYP_MODULE_ENABLED */
#define HAL_ADC_MODULE_ENABLED
#define HAL_CAN_MODULE_ENABLED
/* #define HAL_CEC_MODULE_ENABLED */
/* #define HAL_CRC_MODULE_ENABLED */

Task

1. Create a branch off of dev/can

2. Guard all of the other peripheral files

3. Make a PR. Select dev/can as the base branch