ieee1394: ohci1394: don't leave interrupts enabled during suspend/resume

On my HP 2510p I get the following in dmesg during near the end of most
resumes from suspend to RAM:

irq 19: nobody cared (try booting with the "irqpoll" option)
Pid: 0, comm: swapper Not tainted 2.6.28-rc7 #67
Call Trace:
 <IRQ>  [<ffffffffa00ee9e1>] ? ohci_irq_handler+0x60/0x7e9 [ohci1394]
 [<ffffffff8026aa4d>] __report_bad_irq+0x38/0x87
 [<ffffffff8026abaa>] note_interrupt+0x10e/0x174
 [<ffffffff8026b262>] handle_fasteoi_irq+0xa7/0xd1
 [<ffffffff8020eb87>] do_IRQ+0x73/0xe4
 [<ffffffff8020c626>] ret_from_intr+0x0/0xa
 <EOI>  [<ffffffffa0012606>] ? acpi_idle_enter_bm+0x26b/0x2b2 [processor]
 [<ffffffffa00125fc>] ? acpi_idle_enter_bm+0x261/0x2b2 [processor]
 [<ffffffff8024f30f>] ? notifier_call_chain+0x33/0x5b
 [<ffffffff803b9c64>] ? cpuidle_idle_call+0x8c/0xc4
 [<ffffffff8020b312>] ? cpu_idle+0x4a/0x9a
 [<ffffffff8042c5c8>] ? rest_init+0x5c/0x5e
handlers:
[<ffffffffa00ee981>] (ohci_irq_handler+0x0/0x7e9 [ohci1394])
Disabling IRQ #19

There also seems to be an interrupt storm during suspend/resume when this
happens:
 19:      99968         33   IO-APIC-fasteoi   ohci1394

This patch gets rid of both issues and makes the resume as a whole
significantly faster.

Signed-off-by: Frans Pop <elendil@planet.nl>

As was pointed out in http://lkml.org/lkml/2008/12/6/127, this does not
fix the cause of the interrupt storm.  However, since the source of the
interrupts could not be determined yet, we make the system at least more
usable with this change.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>