msm: kgsl: Update GBIF GX and CX block details for snapshot

GBIF GX and CX blocks use same ID while collecting the debugbus
details from HW but to parse them properly we need unique value.

Hence use unique values for GBIF GX and CX blocks while storing
the data to snapshot dump.

Also update the GMU GX blockID for A615 GPU while reading
the data from HW.

Change-Id: I45cea1497e529f33ebef4ceb8997a66fc9c13453
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>