Bluetooth: Allow to set AMP type for virtual HCI

Type can be changed during re-opening device /dev/vhci.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>