power: pmic: Palmas: Add the base pmic support

Add support to bind the regulators/child nodes with the pmic.
Also adds the pmic i2c based read/write funtions to access pmic
registers.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index 13d293a..1a85566 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -143,3 +143,10 @@
 	FETs and a battery charger. This driver provides register access
 	only, and you can enable the regulator/charger drivers separately if
 	required.
+
+config PMIC_PALMAS
+	bool "Enable driver for Texas Instruments PALMAS PMIC"
+	depends on DM_PMIC
+	---help---
+	The PALMAS is a PMIC containing several LDOs, SMPS.
+	This driver binds the pmic children.