msm: kgsl: Pass the size of IB2 in dwords when saving it in snapshot

The push_object function that saves an IB in snapshot expects the size
of the IB in dwords. The byte-size of IB2 was passed to this function
instead of dwords. Fix this.

Change-Id: I7619696246129da2037338eec1325b80f0c4f321
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>