Bluetooth: btbcm: Make btbcm_initialize() also work for USB connected devices

Make btbcm_initialize() also work for USB connected device,
btbcm_initialize() and btbcm_setup_patchram() are quite similar,
this is a preparation patch for making btbcm_setup_patchram() use
btbcm_initialize() to remove the code duplication.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>