This patch adds a supply regulator to the lp855x platform data to facilitate
powering on/off the 3V rail attached to the controller.

Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: Aaron Durbin <adurbin@chromium.org>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Acked-by: NMilo Kim <milo.kim@ti.com>
Acked-by: NBryan Wu <cooloney@gmail.com>
Acked-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>