Platforms: Fix platform headers

src/platforms/px4_adc.h

src/platforms/px4_app.h

src/platforms/px4_defines.h

src/platforms/px4_i2c.h

src/platforms/px4_log.h

src/platforms/px4_nodehandle.h

src/platforms/px4_posix.h

src/platforms/px4_publisher.h

src/platforms/px4_spi.h

src/platforms/px4_subscriber.h

src/platforms/px4_tasks.h

src/platforms/px4_time.h

src/platforms/px4_workqueue.h