regulator: Fix an s5m8767 build failure

Due to a merge conflict we are getting this:

drivers/regulator/s5m8767.c: In function ‘s5m8767_pmic_probe’:
drivers/regulator/s5m8767.c:575:2: error: implicit declaration of function
‘s5m_reg_write’ [-Werror=implicit-function-declaration]

This is fixed by fully converting this driver to the new s5m API.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
index 5a0d18a..abe64a3 100644
--- a/drivers/regulator/s5m8767.c
+++ b/drivers/regulator/s5m8767.c
@@ -572,21 +572,21 @@
 						pdata->buck2_init +
 						buck_voltage_val2.step);
 
-	s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK2DVS2, buck_init);
+	sec_reg_write(s5m8767->iodev, S5M8767_REG_BUCK2DVS2, buck_init);
 
 	buck_init = s5m8767_convert_voltage_to_sel(&buck_voltage_val2,
 						pdata->buck3_init,
 						pdata->buck3_init +
 						buck_voltage_val2.step);
 
-	s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK3DVS2, buck_init);
+	sec_reg_write(s5m8767->iodev, S5M8767_REG_BUCK3DVS2, buck_init);
 
 	buck_init = s5m8767_convert_voltage_to_sel(&buck_voltage_val2,
 						pdata->buck4_init,
 						pdata->buck4_init +
 						buck_voltage_val2.step);
 
-	s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK4DVS2, buck_init);
+	sec_reg_write(s5m8767->iodev, S5M8767_REG_BUCK4DVS2, buck_init);
 
 	for (i = 0; i < 8; i++) {
 		if (s5m8767->buck2_gpiodvs) {