msm: kgsl: Remove wait for VBIF/GBIF reset ack during soft reset

For A6XX gpu's, soft reset is done using A6XX_RBBM_SW_RESET_CMD
but this reset doesn't reflect GBIF/VBIF reset status in
A6XX_RBBM_VBIF_GX_RESET_STATUS. Remove wait for VBIF/GBIF reset
ack after triggering soft reset to avoid soft reset failures.

Change-Id: Id33f9c67860f6564fee62fa997ca767f2ec88b6b
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>