rtc: rzn1: drop superfluous wday calculation

The week register simply counts from 0 to 6 where the numbers do not
even represent a specific weekday. So we can adopt 'tm_wday' numbering
of the RTC core without converting it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20241122101448.4374-2-wsa+renesas@sang-engineering.com


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