x86/platform/UV: Fix critical UV MMR address error

A critical error was found testing the fixed UV4 HUB in that an MMR address
was found to be incorrect.  This causes the virtual address space for
accessing the MMIOH1 region to be allocated with the incorrect size.

Fixes: 673aa20c

 ("x86/platform/UV: Update uv_mmrs.h to prepare for UV4A fixes")
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Link: https://lkml.kernel.org/r/20180328174011.041801248@stormcage.americas.sgi.com