msm: kgsl: Make snapshot resilient to a non-existent ib1base

During snapshot, we may encounter an invalid IB1 base which
is not found in the current rb. In that case, dump the entire
ringbuffer from start to end and all the IBs in it to get a
more complete picture of the failure.

Change-Id: I4393c7de6f8f4890870fa6e2b5e69073dce922b7
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>