defconfig: sm6150: Enable AMOLED regulator driver for SDMMAGPIE

Enable AMOLED regulator driver to control triple power supply
provided by OLEDB, AB and IBB modules that is used for AMOLED
panels on SM6150/SDMMAGPIE.

Change-Id: I840c2efb53b8dc108d36f601a4aad7070a0b4672
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>