msm: kgsl: Limit number of reads and writes from GPU on SDM670

Limit number of read and write transactions from UCHE block to GBIF
to avoid possible deadlock between GBIF, SMMU and MEMNOC.

This change limits to 8 read and 8 write out standing
transactions at UCHE level.

Change-Id: Ie50e677c041cbc74b7190e54f78e799a59ff5464
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>