drm/xe/vf: Add sanity check for GGTT configuration

The VF GGTT configuration was prepared by the PF, which should be
trusted, was obtained from the GuC, which likely already did some
sanity checks too, but since it's a received data, we should have
our own sanity checks to detect early any misconfiguration.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Reviewed-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Link: https://lore.kernel.org/r/20250602103325.549-4-michal.wajdeczko@intel.com