[PATCH] ppc32: Fix an off-by-one error in ipic_init

There is an off-by-one error in the IPIC code that configures the
external interrupts (Edge or Level Sensitive).

Signed-off-by: Randy Vinson <rvinson@mvista.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>