rtc: rtc-s3c: update IRQ handling

The rtc-s3c.c driver has been using its own ioctl() handling to deal with
alarm and periodic interrupts to handle what should now be done with the
rtc core code.

Change to using the .irq_set_freq and .irq_set_state driver entries and
remove the .ioctl handling.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>