gpio: mockup: don't depend twice on GPIOLIB

config GPIO_MOCKUP is defined in a big if GPIOLIB ... endif block so it
doesn't need to depend explicitly on GPIOLIB.
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20190725131002.14597-1-uwe@kleine-koenig.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -1466,7 +1466,6 @@ endmenu
 
 config GPIO_MOCKUP
 	tristate "GPIO Testing Driver"
-	depends on GPIOLIB
 	select IRQ_SIM
 	help
 	  This enables GPIO Testing driver, which provides a way to test GPIO