dead hvc_console with kdump kernel

[Benjamin Herrenschmidt]

To be more complete, what about a loop that iterates all irq_desc, and
for each of them does

disable_irq()
if (desc->handler->end)
    desc->handler->end()

Or something like that... you could try to test the PENDING and
INPROGRESS flags maybe though that wouldn't handle IPIs (but then, I
think there should be no problem with those if we do an MPIC reset, not
100% clear there)

Ben.