Bluetooth: btusb: Do not require hardcoded interface numbers

Remove hardcoded interface number check because Bluetooth specification
since version 4.0 only recommends and no longer requires specific
interface numbers.

While earlier Bluetooth versions, i.e. 2.1 + EDR and 3.0 + HS, contain
required configuration table in Volume 4 - Host Controller Interface
Part B - USB Transport Layer, Bluetooth Core Specification Addendum 2
changes the table from required to recommended configuration.

Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>