rtc: stm32: drop unused module alias

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

Fixes: 4e64350 ("rtc: add STM32 RTC driver")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250423130318.31244-8-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: jhovold

drivers/rtc/rtc-stm32.c

@@ -1283,7 +1283,6 @@ static struct platform_driver stm32_rtc_driver = {
 
 module_platform_driver(stm32_rtc_driver);
 
-MODULE_ALIAS("platform:" DRIVER_NAME);
 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
 MODULE_DESCRIPTION("STMicroelectronics STM32 Real Time Clock driver");
 MODULE_LICENSE("GPL v2");