msm: kgsl: Dump VBIF and few GPU registers before crash dumper

Triggering Crash Dumper might actually change the values of
few GPU registers including VBIF. Hence dump those registers
ahead and skip them from the list which goes to crash dumper.

Change-Id: I37a53983a65bd8abfefa780053819de71df7f24f
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>