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: NRob Clark <robdclark@gmail.com>

Move this into into adreno_device, and decide based on gpu revision
rather than just assuming a3xx.
Signed-off-by: NRob Clark <robdclark@gmail.com>

We'd rather not duplicate these parts as support for additional gpu
generations is added.
Signed-off-by: NRob Clark <robdclark@gmail.com>