msm: kgsl: Clear the interrupt immediately

Sometimes an interrupt from GPU is ignored while we
are still executing the previous interrupt. In order
to service any interrupt that was fired while executing
the interrupt handler, clear the interrupt register
immediately.
Also, clear the ADRENO_INT_RBBM_AHB_ERROR bit not before
but after it's serviced in its respective handler. This
will avoid firing the main interrupt handler a second
time.

CRs-Fixed: 1072781
Change-Id: Ie6b5a511f5b3077adae7d464de437f2aa893b0c9
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>

Conflicts:
	drivers/gpu/msm/adreno.c
	drivers/gpu/msm/adreno.h

# Conflicts:
#	drivers/gpu/msm/adreno_a5xx.c