drm/i915: Enable KVMGT for BXT.

Enable KVMGT for BXT.
is_supported_device() acting as the gatekeeper of GVT-g init.
If all supported platforms share the same configurations for some
specific feature, platform check will rely on this check only.
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/intel_gvt.c

@@ -47,6 +47,8 @@ static bool is_supported_device(struct drm_i915_private *dev_priv)
 		return true;
 	if (IS_KABYLAKE(dev_priv))
 		return true;
+	if (IS_BROXTON(dev_priv))
+		return true;
 	return false;
 }