echomixer: obsolete usage of dimension information

echomixer: obsolete usage of dimension information

In current implementation for a series of echoaudio drivers, some control
element set delivers information to use element values for
multi-dimensional array. Essentially, ALSA control interface of asound.h
has no common way to parse the information. As a result, the drivers
forces 'echomixer' application to parse the information by several ways.

This issue was reported by a commit 51db452df07b ('Revert "ALSA: echoaudio:
purge contradictions between dimension matrix members and total number of
members"') to Linux kernel. As a result of discussion at Linux
miniconference 2017, usage of 'dimen' member of 'struct snd_ctl_elem_info'
is going to be deprecated for future removal.

According to the above decision, this commit obsoletes usage of 'dimen'
information in 'echomixer' application. In a series of echoaudio drivers,
a control element set named as 'Channels info' includes duplicated
information of the dimension information on value array. Additionally,
some of dimension information have fixed values. This commit utilizes them
to obsolete usage of dimension information.

This patch is tested with Echo Gina 3G.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>