[PATCH] remove unnecessary handle_IRQ_event() prototypes

The function prototype for handle_IRQ_event() in a few architctures is not
needed because they use GENERIC_HARDIRQ.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>