rtc: s3c: drop unused module alias

The driver only support OF probe so drop the unused platform module
alias.

Fixes: ae05c950 ("rtc: s3c: add s3c_rtc_data structure to use variant data instead of s3c_cpu_type")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Fixes: 0d297df0 ("ARM: s3c: simplify platform code")
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250423130318.31244-7-johan+linaro@kernel.org


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>