Revert "tests/kms_plane: Disable GEN12 media compression YUV tests"

This reverts commit 0586d205.

Now that support for YUV engine copy was added, we can re-enable the YUV tests.

Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>