Input: st-keyscan - 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).  This
also fixes !CONFIG_OF error:

  drivers/input/keyboard/st-keyscan.c:251:34: error: ‘keyscan_of_match’ defined but not used [-Werror=unused-const-variable=]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230312131514.351603-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/st-keyscan.c

@@ -259,7 +259,7 @@ static struct platform_driver keyscan_device_driver = {
 	.driver		= {
 		.name	= "st-keyscan",
 		.pm	= pm_sleep_ptr(&keyscan_dev_pm_ops),
-		.of_match_table = of_match_ptr(keyscan_of_match),
+		.of_match_table = keyscan_of_match,
 	}
 };