drm/amd/display: Add prefix for plane functions

This commit adds the amdgpu_dm_plane_ prefix for all functions in the
amdgpu_dm_plane.c. This change enables an easy way to filter code paths
via ftrace.
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -9880,7 +9880,7 @@ static int dm_update_plane_state(struct dc *dc,
 
 		/* Block top most plane from being a video plane */
 		if (plane->type == DRM_PLANE_TYPE_OVERLAY) {
-			if (is_video_format(new_plane_state->fb->format->format) && *is_top_most_overlay)
+			if (amdgpu_dm_plane_is_video_format(new_plane_state->fb->format->format) && *is_top_most_overlay)
 				return -EINVAL;
 
 			*is_top_most_overlay = false;

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.h

@@ -62,5 +62,5 @@ void amdgpu_dm_plane_fill_blending_from_plane_state(const struct drm_plane_state
 				    bool *per_pixel_alpha, bool *pre_multiplied_alpha,
 				    bool *global_alpha, int *global_alpha_value);
 
-bool is_video_format(uint32_t format);
+bool amdgpu_dm_plane_is_video_format(uint32_t format);
 #endif