Bluetooth: Remove dead code for manufacturer inquiry mode quirks

There are some old Bluetooth modules from Silicon Wave and Broadcom
which support Inquiry Result with RSSI, but do not advertise it. The
core has quirks in the code to enable that inquiry mode. However as
it stands right now, that code is not even executed since entering
the function to determine which inquiry mode requires that the device
has the feature bit for Inquiry Result with RSSI set in the first
place. So this makes this dead code that hasn't work for a long
time.

In conclusion, just remove these extra quirks and simplify the setup
of the inquiry mode to be inline and with that a lot easier to read
and understand.

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