pinctrl: lochnagar: select GPIOLIB

In a rare randconfig build I came across one configuration that does
not enable CONFIG_GPIOLIB, which is needed by lochnagar:

ERROR: "devm_gpiochip_add_data" [drivers/pinctrl/cirrus/pinctrl-lochnagar.ko] undefined!
ERROR: "gpiochip_generic_free" [drivers/pinctrl/cirrus/pinctrl-lochnagar.ko] undefined!
ERROR: "gpiochip_generic_request" [drivers/pinctrl/cirrus/pinctrl-lochnagar.ko] undefined!
ERROR: "gpiochip_get_data" [drivers/pinctrl/cirrus/pinctrl-lochnagar.ko] undefined!

Add another 'select' like all other pinctrl drivers have.

Fixes: 0548448b719a ("pinctrl: lochnagar: Add support for the Cirrus Logic Lochnagar")
Signed-off-by: Arnd Bergmann <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Acked-by: Charles Keepax <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/cirrus/Kconfig

···
 config PINCTRL_LOCHNAGAR
 	tristate "Cirrus Logic Lochnagar pinctrl driver"
 	depends on MFD_LOCHNAGAR
+	select GPIOLIB
 	select PINMUX
 	select PINCONF
 	select GENERIC_PINCONF