[MIPS] IP22 Fix brown paper bag in RTC code.

This patch fixes a typo in arch/mips/sgi-ip22/ip22-time.c, leading to the
incorrect year being set into the RTC chip.

Signed-off-by: Julien BLACHE <jb@jblache.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>