drm/i915/gvt: Make intel_gvt_match_device() static

drm/i915/gvt: Make intel_gvt_match_device() static

After the refactor of GVT-g, the reference of intel_gvt_match_device()
only happens in handlers.c. Make it static to let the compiler be
happy.

Fixes: 5cf89ca030a2 ("i915/gvt: Separate the MMIO tracking table from GVT-g")
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Robert Beckett <bob.beckett@collabora.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220427212849.18109-1-zhi.a.wang@intel.com
Reviewed-by: Cc: Jani Nikula <jani.nikula@linux.intel.com>