drm/msm: spin helper

Helper macro to simplify places where we need to poll with timeout
waiting for gpu.

Signed-off-by: Rob Clark <robdclark@gmail.com>

diff --cc drivers/gpu/drm/msm/adreno/a3xx_gpu.c
Simple merge

diff --cc drivers/gpu/drm/msm/adreno/adreno_gpu.c
Simple merge

diff --cc drivers/gpu/drm/msm/adreno/adreno_gpu.h
Simple merge