drm/msm/dpu: Remove unused enum and comment from dpu mdss

Remove enum dpu_iommu_domain from dpu mdss as its unused.

Remove unnecessary comment for variable which is already
removed.
Signed-off-by: NJayant Shekhar <jshekhar@codeaurora.org>
Signed-off-by: NSean Paul <seanpaul@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_mdss.h

@@ -258,12 +258,6 @@ enum dpu_vbif {
 	VBIF_NRT = VBIF_1
 };
 
-enum dpu_iommu_domain {
-	DPU_IOMMU_DOMAIN_UNSECURE,
-	DPU_IOMMU_DOMAIN_SECURE,
-	DPU_IOMMU_DOMAIN_MAX
-};
-
 /**
  * DPU HW,Component order color map
  */
@@ -358,7 +352,6 @@ enum dpu_3d_blend_mode {
  * @alpha_enable: whether the format has an alpha channel
  * @num_planes: number of planes (including meta data planes)
  * @fetch_mode: linear, tiled, or ubwc hw fetch behavior
- * @is_yuv: is format a yuv variant
  * @flag: usage bit flags
  * @tile_width: format tile width
  * @tile_height: format tile height