pinctrl: pinctrl-microchip-sgpio: Add OF config dependency

The pinctrl-microchip-sgpio driver needs OF support, so add that to
Kconfig.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20201125122014.11237-1-lars.povlsen@microchip.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/Kconfig

@@ -376,11 +376,13 @@ config PINCTRL_OCELOT
 
 config PINCTRL_MICROCHIP_SGPIO
 	bool "Pinctrl driver for Microsemi/Microchip Serial GPIO"
+	depends on OF
 	depends on HAS_IOMEM
 	select GPIOLIB
 	select GENERIC_PINCONF
 	select GENERIC_PINCTRL_GROUPS
 	select GENERIC_PINMUX_FUNCTIONS
+	select OF_GPIO
 	help
 	  Support for the serial GPIO interface used on Microsemi and
 	  Microchip SoC's. By using a serial interface, the SIO