rtc: efi: Remove the repeated module alias

'MODULE_ALIAS' is declared twice, cleanup one.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1621848834-20857-1-git-send-email-zhangshaokun@hisilicon.com