msm: kgsl: Avoid parsing IBs during atomic snapshot

During IB parse, vmalloc is called which can sleep and
should not be called from atomic context. Since IBs are not
dumped during atomic snapshot, there is no need to parse it.

Change-Id: I116d095958d99a8caeafb24dc45684ead01c961d
Signed-off-by: Kamal Agrawal <kamaagra@codeaurora.org>