drm/msm/adreno: bit of init refactoring

Push a few bits down into adreno_gpu so they won't have to be duplicated
as support for additional adreno generations is added.

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_device.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