rtc: sc27xx: Remove clearing SPRD_RTC_POWEROFF_ALM_FLAG flag

The SPRD_RTC_POWEROFF_ALM_FLAG flag is used to indicate if a poweroff alarm
is set, which can power on the system when system in power-off status.

And the bootloader will validate this flag to check if the booting mode is
alarm booting mode, thus we should not clear this flag in kernel, instead
bootloader will clear this flag after checking the booting mode.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Link: https://lore.kernel.org/r/1f75310242de75b14d8973538bf96efffb395daf.1567666894.git.baolin.wang@linaro.org


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