msm: kgsl: Fix the missing IBs from the snapshot

We missed updating index for internal IBs like setstate
or power-on fixup.

The index value was never updated after that, so all the
IBs after that index were never parsed, and are missing
from the snapshot.

Change-Id: I61db75f33630db322fe5ee1adce9f120987d32ee
Signed-off-by: Sunil Khatri <sunilkh@codeaurora.org>