mei: nfc: clean nfc internal struct on host exit

NFC internal structure cleaning was dropped by commit

commit 48705693
Author: Tomas Winkler <tomas.winkler@intel.com>
Date:   Mon Feb 17 15:13:19 2014 +0200

    mei: Remove all bus devices from the mei_dev list when stopping the MEI

    When stopping the MEI, we should remove and potentially unregister
    all bus devices queued on the mei_dev linked list.

We allocate nfc_dev and free it across the reset
so we do not keep it in dirty state

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>