drivers: gpio: implement PALMAS GPIO cell

Add gpio driver for TI Palmas series PMIC. This has 8 gpio which can
work as input/output.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 250f1eb..63e62e1 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -435,6 +435,13 @@
 	help
 	  Say yes here to support Vybrid vf610 GPIOs.
 
+config PALMAS_GPIO
+	bool "TI PALMAS series PMICs GPIO"
+	depends on DM_GPIO && PMIC_PALMAS
+	help
+	  Select this option to enable GPIO driver for the TI PALMAS
+	  series chip family.
+
 config PIC32_GPIO
 	bool "Microchip PIC32 GPIO driver"
 	depends on DM_GPIO && MACH_PIC32