msm: kgsl: Dump GMU debug bus data from GX and CX blocks

GMU debug bus data is available from both GX and CX blocks. Dump it
out so we get more snapshot data.

Change-Id: I5a8a78b91d899586f0d84fb21f07a4da47b14427
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>