gpiolib: Add missing dummies for the unified device properties interface
If GPIOLIB=n:
drivers/leds/leds-gpio.c: In function ‘gpio_leds_create’:
drivers/leds/leds-gpio.c:187: error: implicit declaration of function ‘devm_get_gpiod_from_child’
drivers/leds/leds-gpio.c:187: warning: assignment makes pointer from integer without a cast
Add dummies for fwnode_get_named_gpiod() and devm_get_gpiod_from_child()
for the !GPIOLIB case to fix this.