disp: msm: sde: use proper API to retrieve connector state in check phase

Use sde_connector_state_get_topology API instead of
drm_atomic_get_connector_state since the latter can
return a blank connector state if not found in
global atomic state.

Change-Id: Ib5b58c6cab438a367a885308341d6bccc624f777
Signed-off-by: Amine Najahi <anajahi@codeaurora.org>

msm/sde/sde_rm.c

@@ -2147,7 +2147,8 @@ bool sde_rm_topology_is_group(struct sde_rm *rm,
 			continue;
 		}
 
-		conn_state = drm_atomic_get_connector_state(state->state, conn);
+		conn_state = drm_atomic_get_new_connector_state(state->state,
+				conn);
 		if (!conn_state) {
 			SDE_DEBUG("%s invalid connector state\n", conn->name);
 			continue;