clk: rockchip: mark pclk_ddrupctl as critical_clock on rk3036

No driver to handle this clk yet, but chip design requiress for this clock
supplying the ddr controller to be always on.

Signed-off-by: Elaine Zhang <[e-mail]>
Signed-off-by: Heiko Stuebner <[e-mail]>

drivers/clk/rockchip/clk-rk3036.c

···
 	"aclk_peri",
 	"hclk_peri",
 	"pclk_peri",
+	"pclk_ddrupctl",
 };
 
 static void __init rk3036_clk_init(struct device_node *np)