power: Add support for RK808 regulators

Add regulator support for the RK808 PMIC. It integrated 4 BUCKs and 8 LDOs
all of which are supported by this driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 434dd02..8f638a9 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -49,6 +49,15 @@
 	features for fixed value regulators. The driver implements get/set api
 	for enable and get only for voltage value.
 
+config REGULATOR_RK808
+	bool "Enable driver for RK808 regulators"
+	depends on DM_REGULATOR && PMIC_RK808
+	---help---
+	Enable support for the regulator functions of the RK808 PMIC. The
+	driver implements get/set api for the various BUCKS and LDOs supported
+	by the PMIC device. This driver is controlled by a device tree node
+	which includes voltage limits.
+
 config REGULATOR_S5M8767
 	bool "Enable support for S5M8767 regulator"
 	depends on DM_REGULATOR && PMIC_S5M8767