drm/vc4: dsi: Add correct stop condition to vc4_dsi_encoder_disable iteration

vc4_dsi_encoder_disable is partially an open coded version of
drm_bridge_chain_disable, but it missed a termination condition
in the loop for ->disable which meant that no post_disable
calls were made.

Add in the termination clause.

Fixes: 033bfe75 ("drm/vc4: dsi: Fix bridge chain handling")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-17-maxime@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_dsi.c

@@ -803,6 +803,9 @@ static void vc4_dsi_encoder_disable(struct drm_encoder *encoder)
 	list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
 		if (iter->funcs->disable)
 			iter->funcs->disable(iter);
+
+		if (iter == dsi->bridge)
+			break;
 	}
 
 	vc4_dsi_ulps(dsi, true);