Bluetooth: Separate AMP controller type from HCI device type

There are two defined HCI device types. One is for BR/EDR controllers
and the other is for AMP controllers. The HCI device type is not the
same as the AMP controller type. It just happens that currently the
defined types match, but that is not guaranteed.

Split the usage of AMP controller type into its own domain so that
it is possible to separate between BR/EDR controllers, 802.11 AMP
controllers and any other AMP technology that might be defined in
the future.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>