rtc: sh: remove useless wrapper function

The wrapper to enable interrupts is so thin that we can use it directly.
Also gets rid of an 'inline' which doesn't make sense here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20250227134256.9167-16-wsa+renesas@sang-engineering.com


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