main: add triggerhappy
Created by: alive4ever
Add triggerhappy package.
Note that triggerhappy build depends on linux-headers package, which probably differs between kernel version.
Build tested with alpine armhf linux-headers 4.4.6-r2 package. Run tested on armani, with the following result:
/dev/input/event0 generates ABS_MT_TRACKING_ID, ABS_MT_POSITION_X, ABS_MT_POSITION_Y, ABS_MT_TOUCH_MAJOR /dev/input/event1 handles KEY_VOLUMEUP. /dev/input/event2 handles KEY_VOLUMEDOWN and KEY_POWER.