UEAGLE: Devolo and Elsa chipsets support

Support for Devolo and Elsa chipsets. These chipsets have no information
about ADSL annex (line type) encoded in USB descriptors. Driver try to
get this information from USB VID and PID or it can be explicitly set by
the user through module parameter. Thanks to Johann Hanne, whose make
most of this patch.

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>