Ad hoc fix of command API

Add initial files for RN-42

Fix for new API(key_t to keypos_t)

Fix timer.h to include AVR specific header

Port action_* to mbed

Merge branch 'mbed' into dev

Add checksum tool for NXP LPC

Add LED indicator support in mbed

Port ps2_usb to mbed

Fix build files for mbed

Fix common files for mbed

Fix debug.h and remove debug_config.h

Port action_* to mbed

Fix print and timer

Port timer to mbed

Add keyboard/mbed_onekey

Just ignore ADB Service Request

- to support Adjustable keyboard(composite device?)

Fix 'debug-off' target of hhkb to remove 'print'

Fix NKRO code when NKRO is disable

Fix READEM of hhkb and doc/build.md