drm/amd/display: Make assert in DCE's program_bit_depth_reduction more lenient.

This is needed to avoid warnings with linebuffer depth 36 bpp.
Testing on a Polaris11, DCE-11.2 on a 10 bit HDR-10 monitor
showed no obvious problems, and this 12 bpc limit is consistent
with what other function in the DCE bit depth reduction path use.

Signed-off-by: Mario Kleiner <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dce/dce_transform.c

···
 	enum dcp_out_trunc_round_mode trunc_mode;
 	bool spatial_dither_enable;
 
-	ASSERT(depth < COLOR_DEPTH_121212); /* Invalid clamp bit depth */
+	ASSERT(depth <= COLOR_DEPTH_121212); /* Invalid clamp bit depth */
 
 	spatial_dither_enable = bit_depth_params->flags.SPATIAL_DITHER_ENABLED;
 	/* Default to 12 bit truncation without rounding */
···
 	enum dcp_out_trunc_round_mode trunc_mode;
 	bool spatial_dither_enable;
 
-	ASSERT(depth < COLOR_DEPTH_121212); /* Invalid clamp bit depth */
+	ASSERT(depth <= COLOR_DEPTH_121212); /* Invalid clamp bit depth */
 
 	spatial_dither_enable = bit_depth_params->flags.SPATIAL_DITHER_ENABLED;
 	/* Default to 12 bit truncation without rounding */