gpio: visconti: drop of_match_ptr for ID table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might not be relevant here).

  drivers/gpio/gpio-visconti.c:187:34: error: ‘visconti_gpio_of_match’ defined but not used [-Werror=unused-const-variable=]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-visconti.c

@@ -194,7 +194,7 @@ static struct platform_driver visconti_gpio_driver = {
 	.probe		= visconti_gpio_probe,
 	.driver		= {
 		.name	= "visconti_gpio",
-		.of_match_table = of_match_ptr(visconti_gpio_of_match),
+		.of_match_table = visconti_gpio_of_match,
 	}
 };
 module_platform_driver(visconti_gpio_driver);