msm: kgsl: Fix snapshot collection for ib1

Sometimes IB1_BASE from register does not match with IB1 of the
ring buffer, this may happen while doing save restore of IB
during preemption. In such case, to dump IB1 in snapshot, check
for overlap between IB1_BASE and IB1 from the ring buffer and
dump IB1 in snapshot as per ring buffer's IB1 base and size.

Change-Id: Ic3af8678a11f20f447fcbcbd3ec209283619b96a
Signed-off-by: Pankaj Gupta <gpankaj@codeaurora.org>