drm/msm: Pass the MMU domain index in struct msm_file_private

Pass the index of the MMU domain in struct msm_file_private instead
of assuming gpu->id throughout the submit path. This clears the way
to change ctx->aspace to a per-instance pagetable.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/msm_gem.h

@@ -141,6 +141,7 @@ void msm_gem_free_work(struct work_struct *work);
 struct msm_gem_submit {
 	struct drm_device *dev;
 	struct msm_gpu *gpu;
+	struct msm_gem_address_space *aspace;
 	struct list_head node;   /* node in ring submit list */
 	struct list_head bo_list;
 	struct ww_acquire_ctx ticket;