drm/i915/gvt: Refine dmabuf_obj cleanup process

In the process of dmabuf_obj cleanup, the dmabuf_obj might be freed during
dmabuf_obj_put leaking intel_gvt_hypervisor_put_vfio_device.

Move intel_gvt_hypervisor_put_vfio_device and all the other dmabuf_obj ops
in front of dmabuf_obj_put and let every dmabuf_obj have a chance to call
intel_gvt_hypervisor_put_vfio_device to fix this leaking issue.

Fixes: e3a0d7976c53 ("drm/i915/gvt: Handle orphan dmabuf_objs")
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>