rtc: s3c: quiet maybe-unused variable warning

When CONFIG_OF is disabled then the matching table is not referenced.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20210202112934.3612726-2-alexandre.belloni@bootlin.com

drivers/rtc/rtc-s3c.c

@@ -558,7 +558,7 @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
 	.disable		= s3c6410_rtc_disable,
 };
 
-static const struct of_device_id s3c_rtc_dt_match[] = {
+static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
 	{
 		.compatible = "samsung,s3c2410-rtc",
 		.data = &s3c2410_rtc_data,