vfio-mdev: de-polute the namespace, rename parent_device & parent_ops

Add an mdev_ prefix so we're not poluting the namespace so much.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

samples/vfio-mdev/mtty.c

@@ -1402,7 +1402,7 @@ struct attribute_group *mdev_type_groups[] = {
 	NULL,
 };
 
-struct parent_ops mdev_fops = {
+struct mdev_parent_ops mdev_fops = {
 	.owner                  = THIS_MODULE,
 	.dev_attr_groups        = mtty_dev_groups,
 	.mdev_attr_groups       = mdev_dev_groups,