drm/amd/display: Calculate output_color_space after pixel encoding adjustment

Code in get_output_color_space depends on knowing the pixel encoding to
determine whether to pick between eg. COLOR_SPACE_SRGB or
COLOR_SPACE_YCBCR709 for transparent RGB -> YCbCr 4:4:4 in the driver.

v2: Fixed patch being accidentally based on a personal feature branch, oops!

Fixes: ea117312 ("drm/amd/display: Reduce HDMI pixel encoding if max clock is exceeded")
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

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

@@ -5311,8 +5311,6 @@ static void fill_stream_properties_from_drm_display_mode(
 
 	timing_out->aspect_ratio = get_aspect_ratio(mode_in);
 
-	stream->output_color_space = get_output_color_space(timing_out);
-
 	stream->out_transfer_func->type = TF_TYPE_PREDEFINED;
 	stream->out_transfer_func->tf = TRANSFER_FUNCTION_SRGB;
 	if (stream->signal == SIGNAL_TYPE_HDMI_TYPE_A) {
@@ -5323,6 +5321,8 @@ static void fill_stream_properties_from_drm_display_mode(
 			adjust_colour_depth_from_display_info(timing_out, info);
 		}
 	}
+
+	stream->output_color_space = get_output_color_space(timing_out);
 }
 
 static void fill_audio_info(struct audio_info *audio_info,