defconfig: Compile GFX LDO regulator driver for msmfalcon

GFX LDO regulator driver powers GPU subsystem in msmfalcon. This
LDO regulator is CPR managed. Enable GFX LDO regulator and platform
specific MMSS CPR regulator to be compiled for msmfalcon.

CRs-Fixed: 1068294
Change-Id: I2111fe55c9335d57ac91f18f4a4fb3689d80660d
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>