msm: kgsl: Read CP_IB registers before hardware dump

Read the CP_IB registers before dumping the hardware state
in snapshot and use these read values when dumping the
IB sections. This is needed because the hardware dump
resets the CP registers and hence the CP register values
need to be read before dumping hardware state.

Change-Id: Ic08570c21b4f6b8da81e771ba47df51b1d97c1f3
CRs-Fixed: 724758
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>