ucm2: USB-Audio: Add CaptureMixerElem for Lenovo ThinkStation P620

[GitHub pull_request - opened]

alsa-project/alsa-ucm-conf pull request #51 was opened from khfeng:

The Switch and Volume mixer start to work after device firmware update.
Add MixerElem to support them.

Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>

Request URL   : https://github.com/alsa-project/alsa-ucm-conf/pull/51
Patch URL     : https://github.com/alsa-project/alsa-ucm-conf/pull/51.patch
Repository URL: https://github.com/alsa-project/alsa-ucm-conf