staging: most: core: remove processing of deprecated names

The USB HDM does not use the "@" character for channel names anymore. This
patch cleans up the code processing such names and adapts the corresponding
examples on how to use the properties "add_link" and "remove_link".

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>