drivers:input:vl53l0x add sensor identify sysfs interface for vl53l0x

add a sysfs interface for vl53l0x to identify two vl53l0x sensors on board.

Change-Id: Idf4ff78f0c254c6b1fd1a897be5221ce897d29e8
Signed-off-by: Chaojun Wang <chaojun@codeaurora.org>