When CONFIG_PM is enabled, it uses the TOY_MATCH2 interrupt as the system

timer tick. Prior to this patch, if IDE IRQ probing occured, then the
TOY_MATCH2 interrupt would be permanently disabled, and no system timer
tick occurs. This patch corrects this situation by correctly registering
the TOY_MATCH2 interrupt so that IDE IRQ probing doesn't have adverse
side effects.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>