x86/platform/UV: Initialize PCH GPP_D_0 NMI Pin to be NMI source

The initialize PCH NMI I/O function is separate and may be moved to BIOS
for security reasons.  This function detects whether the PCH NMI config
has already been done and if not, it will then initialize the PCH here.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Russ Anderson <rja@hpe.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170125163518.089387859@asylum.americas.sgi.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>