[PATCH] m68knommu: enable_irq/disable_irq

mach_enable_irq/mach_disable_irq are never actually set, so let's remove
them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>