mfd: Rename s5m file and directories to samsung

Previously, Samsung PMIC naming rule start with prefix of s5m.
But Naming rule is changed.
From now on, Prefix will be changed to s2m.
So, To support pmic series of s5m and s2m, change mfd file and directory name.

Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index c86b886..12c0c0e 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -235,7 +235,7 @@
 
 config REGULATOR_S5M8767
 	tristate "Samsung S5M8767A voltage regulator"
-	depends on MFD_S5M_CORE
+	depends on MFD_SEC_CORE
 	help
 	 This driver supports a Samsung S5M8767A voltage output regulator
 	 via I2C bus. S5M8767A have 9 Bucks and 28 LDOs output and