drm/xe: Add page queue multiplier

For an unknown reason the math to determine the PF queue size does is
not correct - compute UMD applications are overflowing the PF queue
which is fatal. A multippier of 8 fixes the problem.

Fixes: 3338e4f9 ("drm/xe: Use topology to determine page fault queue size")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Jagmeet Randhawa <jagmeet.randhawa@intel.com>
Link: https://lore.kernel.org/r/20250408155915.78770-1-matthew.brost@intel.com