I noticed an occasional crash on wakeup from sleep on my powerbook
(strangly never happened before, probably timing related) that appears to
be due to a dangling interrupt while the chip is put to sleep and beeing
reset on wakeup.

This patch fixes is by disabling the irq in the ide pmac driver while
asleep and only re-enable it after the chip has been fully reset.  This is
safe to do so as the interrupt of these apple IDE cells is never shared.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>