rtc: davinci: remove useless 24h alarm handling

The code handling invalid alarms meaning the alarm is in the next 24 hours
is not necessary since commit f8245c26 ("rtc: remove "RTC_ALM_SET mode"
bugs") which actually predates this driver. Since then, .set_alarm is never
called with an invalid alarm and this handling is not necessary in the
driver.

Link: https://lore.kernel.org/r/20200305215022.32533-2-alexandre.belloni@bootlin.com


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