CrKbd with the Trackpad support

CrKbd version that supports BlackBerry 8520 trackpad via additional PCB. See this repository for more details:

• https://github.com/vlukash/corne-trackpad
• https://vlukash.com/2019/01/15/trackpad-in-keycap-corne-crkbd-keyboard

This firmware is for the Left keyboard.

Build

make crkbd:vlukash_trackpad_left:dfu