rtc: s3c: quiet maybe-unused variable warning

When CONFIG_OF is disabled then the matching table is not referenced.

Signed-off-by: Alexandre Belloni <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/rtc/rtc-s3c.c

···
 	.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,