[Bluetooth] Add parameters to control BNEP header compression

The Bluetooth qualification for PAN demands testing with BNEP header
compression disabled. This is actually pretty stupid and the Linux
implementation outsmarts the test system since it compresses whenever
possible. So to pass qualification two need parameters have been added
to control the compression of source and destination headers.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>