gpio: mockup: verify the number of GPIO chips requested

The number of supported mockup chips is limited. Check this limit when
parsing the module parameters.

Also: make sure that each chip is described with a <base - ngpio> pair.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mockup.c

@@ -330,7 +330,9 @@ static int __init gpio_mockup_init(void)
 {
 	int err;
 
-	if (gpio_mockup_params_nr < 2 || (gpio_mockup_params_nr % 2))
+	if ((gpio_mockup_params_nr < 2) ||
+	    (gpio_mockup_params_nr % 2) ||
+	    (gpio_mockup_params_nr > GPIO_MOCKUP_MAX_RANGES))
 		return -EINVAL;
 
 	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);