gpio: mockup: deprecate the old testing module

We have a much better alternative to the clunky old gpio-mockup. Don't
remove it just yet (there are tests depending on it out there) but make
Kconfig say that it should no longer be used in new projects.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -1790,9 +1790,11 @@ config GPIO_LATCH
 	  connected to other GPIOs.
 
 config GPIO_MOCKUP
-	tristate "GPIO Testing Driver"
+	tristate "GPIO Testing Driver (DEPRECATED)"
 	select IRQ_SIM
 	help
+	  This module is DEPRECATED. Please consider using gpio-sim instead.
+
 	  This enables GPIO Testing driver, which provides a way to test GPIO
 	  subsystem through sysfs (or char device) and debugfs.
 	  User could use it through the script in