Add hardware key overlays

Change-Id: I025a6aec71e223385a5bf0d2fde4f3ed6f5beaf5
Merge branch 'cm-12.0' of https://github.com/CyanogenMod/android_device_lge_hammerhead into lp5.0

Signed-off-by: scott <scott@ubuntu>

Conflicts:
	overlay/frameworks/base/core/res/res/values/config.xml