msm: kgsl: Add GPU_UCHE_GBIF_GX_CONFIG to powerup register list

GPU_UCHE_GBIF_GX_CONFIG is programmed as a part of software
workaround for HW errata#171. Add this to IFPC powerup register
list to make sure its value is restored when GPU comes out of
IFPC.

Change-Id: I59c7bfd87551d0a61dec9414e5f7c1a2688c3960
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>