msm: kgsl: Reduce VBIF outstanding transactions for 8916

Reduce VBIF read and  write outstanding transactions to
10 to limit the bandwidth from GPU. This may help
to reduce the memory latencies for other real time
masters like modem at system level.

Change-Id: Ie762c96ad973d9b81fde5121ced624d4ac8275c2
Signed-off-by: Sreedhar Telukuntla <stelukun@codeaurora.org>