Bluetooth: Use separate function for BCM92035 vendor setup

Trying to squeeze every single vendor setup routine into the same function
and have it assigned all the time is actually a bad idea. Especially since
the core can handle the absence of a setup routine perfectly fine.

To make this a lot simpler for future additions of vendor setup code,
split the BCM92035 setup into its own function and only assign it when
this specific device has been detected.

Doing it like this has the nice side benefit that we do not have to keep
a copy of the driver_info around.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>