msm: kgsl: Update snapshot ringbuffer parser for type7 ibs

Fix the wraparound logic when searching for ibs in the ringbuffer.
The ibs can either be type3 or type7 packets so handle both cases.

CRs-Fixed: 971163
Change-Id: I9bc4b4a72cddfe7f3d3892612c6e28861fdd0324
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>