clk: keystone: make use of of_clk_parent_fill helper function

Use of_clk_parent_fill to fill in the parent clock names' array.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/keystone/pll.c

@@ -309,8 +309,7 @@ static void __init of_pll_mux_clk_init(struct device_node *node)
 		return;
 	}
 
-	parents[0] = of_clk_get_parent_name(node, 0);
-	parents[1] = of_clk_get_parent_name(node, 1);
+	of_clk_parent_fill(node, parents, 2);
 	if (!parents[0] || !parents[1]) {
 		pr_err("%s: missing parent clocks\n", __func__);
 		return;