mfd: s2mps11: Add device tree support

This patch adds DT compatible string for s2mps11 and binding documentation.

Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/sec-core.c

@@ -69,6 +69,9 @@ static struct of_device_id sec_dt_match[] = {
 	{	.compatible = "samsung,s5m8767-pmic",
 		.data = (void *)S5M8767X,
 	},
+	{	.compatible = "samsung,s2mps11-pmic",
+		.data = (void *)S2MPS11X,
+	},
 	{},
 };
 #endif