drm/amd/display: Move and Rename "is_stream_changed()"

 -Move "is_stream_changed()" to DC interface
 -Rename "is_stream_changed()" to "dc_is_stream_changed()"

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 63fd5b3..0918569 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -534,6 +534,8 @@ struct dc_stream_update {
 	struct dc_transfer_func *out_transfer_func;
 };
 
+bool dc_is_stream_unchanged(
+	struct dc_stream *old_stream, struct dc_stream *stream);
 
 /*
  * Setup stream attributes if no stream updates are provided