delete drv_gpio.h, modules/gpio_led, and fmu GPIO ioctls

ROMFS/px4fmu_common/init.d/airframes/4004_H4_680mm

boards/aerotenna/ocpoc/ubuntu.cmake

boards/airmind/mindpx-v2/default.cmake

boards/airmind/mindpx-v2/src/board_config.h

boards/atlflight/eagle/default.cmake

boards/atlflight/excelsior/default.cmake

boards/atmel/same70xplained/default.cmake

boards/atmel/same70xplained/src/board_config.h

boards/auav/x21/default.cmake

boards/auav/x21/src/board_config.h

boards/av/x-v1/default.cmake

boards/av/x-v1/src/board_config.h

boards/beaglebone/blue/cross.cmake

boards/beaglebone/blue/native.cmake

boards/bitcraze/crazyflie/default.cmake

boards/emlid/navio2/cross.cmake

boards/emlid/navio2/native.cmake

boards/gumstix/aerocore2/default.cmake

boards/gumstix/aerocore2/src/board_config.h

boards/intel/aerofc-v1/default.cmake