When removing a device from an iommu group, the domain should
be detached from the device. Otherwise, the stale domain info
will still be cached by the driver and the driver will refuse
to attach any domain to the device again.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Fixes: b7297783 ("iommu/vt-d: Remove duplicated code for device hotplug")
Reported-and-tested-by: NVlad Buslov <vladbu@mellanox.com>
Suggested-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lkml.org/lkml/2019/7/26/1133Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>