Samsung touchscreens support using double-tap to wake to trigger
always on display. Implement support for the sysfs API used to
en/disable this. Note that this requires a kernel change to send
KEY_POWER on the dt2w event instead of KEY_BLACK_UI_GESTURE - e.g.
b783d5e0fd
[Linux4: This makes DT2W work on full screen instead of only lower half]
Change-Id: I80898c8810216a90cc11b4e8b0f12a1918cd17a3
Signed-off-by: roynatech2544 <whiteshell2544@naver.com>