rtc: tps65910: allow using RTC without alarm interrupt

If tps65910 INT1 pin (IRQ output) is not wired to any IRQ controller,
then it can't be used as system wakeup/alarm source,
but it is still possible to read/write time from/to RTC.

Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://lore.kernel.org/r/20191116203748.27166-1-andrej.skvortzov@gmail.com


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