staging: most: core: consolidate channel attributes

This patch replaces 13 temporary variables representing the attributes
to control the channel with an array of 13 elements to keep the
corresponding code compact.

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>