Merge pull request #3880 from haukepetersen/rm_hwtimer_leftovers

boards/arduino-due/include/board.h

boards/arduino-mega2560/include/board.h

boards/avsextrem/include/board.h

boards/cc2538dk/include/board.h

boards/ek-lm4f120xl/include/board.h

boards/f4vi1/include/board.h

boards/fox/include/board.h

boards/limifrog-v1/include/board.h

boards/mbed_lpc1768/include/board.h

boards/msbiot/include/board.h

boards/mulle/board.c

boards/mulle/include/board.h

boards/nrf51dongle/include/board.h

boards/nrf6310/include/board.h

boards/nucleo-f091/include/board.h

boards/nucleo-f303/include/board.h

boards/nucleo-f334/include/board.h

boards/nucleo-l1/include/board.h

boards/openmote/include/board.h

boards/pttu/include/board.h