When sending a NMI_VECTOR IPI using the UV_HUB_IPI_INT register,
we need to ensure the delivery mode field of that register has
NMI delivery selected.

This makes those IPIs true NMIs, instead of flat IPIs. It
matters to reboot sequences and KGDB, both of which use NMI
IPIs.
Signed-off-by: NRobin Holt <holt@sgi.com>
Acked-by: NJack Steiner <steiner@sgi.com>
Cc: Martin Hicks <mort@sgi.com>
Cc: <stable@kernel.org>
LKML-Reference: <20091020193620.877322000@alcatraz.americas.sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>