lights: Adding keypad alt/shift LED light IDs

in conjunction with the alt/shift light patch for
frameworks/base:
http://review.cyanogenmod.org/#/c/34903/

Change-Id: Ie97a80d398d474950340cba60c48ba5904978ec5
Merge branch 'cm-10.1' of https://github.com/CyanogenMod/android_hardware_libhardware into cm-10.1