frv: Remove bogus NO_IRQ = -1 define

The old NO_IRQ define some platforms had was long ago declared obsolete
and wrong. FRV should therefore not be re-introducing this, especially as
IRQs are usually unsigned in the kernel. The "no IRQ" case is defined to be
zero and Linus made this rather clear at the time.

arch/frv shows no dependancy on this but it might show up driver fixes
needing doing I guess

Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>