Merge pull request #6829 from francois-berder-imgtec/periph-gpio

boards/pic32-clicker/Makefile.features

boards/pic32-clicker/clicker.c

boards/pic32-clicker/include/board.h

boards/pic32-clicker/include/periph_conf.h

boards/pic32-wifire/Makefile.features

boards/pic32-wifire/include/board.h

boards/pic32-wifire/include/periph_conf.h

boards/pic32-wifire/wifire.c

cpu/mips_pic32_common/Makefile.include

cpu/mips_pic32_common/include/periph_cpu_common.h

cpu/mips_pic32_common/periph/gpio.c

cpu/mips_pic32mx/Makefile.include

cpu/mips_pic32mx/include/periph_cpu.h

cpu/mips_pic32mz/Makefile.include

cpu/mips_pic32mz/include/periph_cpu.h