bus: ti-sysc: Fix sysc_unprepare() when no clocks have been allocated

If we return early before ddata->clocks have been allocated we will get a
NULL pointer dereference in sysc_unprepare(). Let's fix this by returning
early when no clocks are allocated.

Fixes: 0eecc636 ("bus: ti-sysc: Add minimal TI sysc interconnect target driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/bus/ti-sysc.c

@@ -1331,6 +1331,9 @@ static void sysc_unprepare(struct sysc *ddata)
 {
 	int i;
 
+	if (!ddata->clocks)
+		return;
+
 	for (i = 0; i < SYSC_MAX_CLOCKS; i++) {
 		if (!IS_ERR_OR_NULL(ddata->clocks[i]))
 			clk_unprepare(ddata->clocks[i]);