rtc: s5m: use shorter time of register update

rtc: s5m: use shorter time of register update

Set the time needed for updating alarm and time registers to 0.45 ms.
The default is 7.32 ms which is too long and leads to warnings when
setting alarm or time:

	s5m-rtc: waiting for UDR update, reached max number of retries

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Cc: Kyungmin Park <[email protected]>
Cc: Lee Jones <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Sangbeom Kim <[email protected]>
Cc: Samuel Ortiz <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>