mfd: sec: Add clock cell for s2mps11

This patch adds clock to list of mfd cells for s2mps11 and DT documentation
for clock part.

Reviewed-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/sec-core.c

@@ -61,7 +61,9 @@ static struct mfd_cell s5m8767_devs[] = {
 static struct mfd_cell s2mps11_devs[] = {
 	{
 		.name = "s2mps11-pmic",
-	},
+	}, {
+		.name = "s2mps11-clk",
+	}
 };
 
 #ifdef CONFIG_OF