Our usual i915 convention is to assume that future platforms will follow
the same behavior as the latest platform of today.  The VDBOX/SFC
capabilities described here don't seem like something that should be
specific to TGL, so let's future-proof by making the test apply to all
gen12+ platforms.

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191224231521.3430660-1-matthew.d.roper@intel.comReviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>