drm/amd/display: Do DC mode-change check after stream creation

Do DC level mode change checks (via dc_stream_state) only when creating
a new stream, as this check is uneccessary without a new dc_stream_state
anyways. Doing so better demonstrates the intent of this mode-change
check, in comparison to guarding it with the 'enable' flag.
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -4513,17 +4513,14 @@ static int dm_update_crtcs_state(struct dc *dc,
 						__func__, acrtc->base.base.id);
 				break;
 			}
-		}
 
-		if (enable && dc_is_stream_unchanged(new_stream, dm_old_crtc_state->stream) &&
+			if (dc_is_stream_unchanged(new_stream, dm_old_crtc_state->stream) &&
 			    dc_is_stream_scaling_unchanged(new_stream, dm_old_crtc_state->stream)) {
-
 				new_crtc_state->mode_changed = false;
-
 				DRM_DEBUG_DRIVER("Mode change not required, setting mode_changed to %d",
 						 new_crtc_state->mode_changed);
 			}
-
+		}
 
 		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
 			goto next_crtc;