drivers: gpio: implement MAX77663 GPIO cell

MAXIM Semiconductor's PMIC, MAX77663 has 8 GPIO pins and 3 GPIO-like
pins. It also supports interrupts from these pins.

Add GPIO driver for these pins to control via GPIO APIs.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c8b3fd7..dab3eb9 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -68,6 +68,7 @@
 obj-$(CONFIG_SIFIVE_GPIO)	+= sifive-gpio.o
 obj-$(CONFIG_NOMADIK_GPIO)	+= nmk_gpio.o
 obj-$(CONFIG_MAX7320_GPIO)	+= max7320_gpio.o
+obj-$(CONFIG_$(SPL_)MAX77663_GPIO)	+= max77663_gpio.o
 obj-$(CONFIG_SL28CPLD_GPIO)	+= sl28cpld-gpio.o
 obj-$(CONFIG_ZYNQMP_GPIO_MODEPIN)	+= zynqmp_gpio_modepin.o
 obj-$(CONFIG_SLG7XL45106_I2C_GPO)	+= gpio_slg7xl45106.o