ucm: remove MixerName

Now that MixerName has been removed across the repo we can remove it
from our code

BUG=chromium:1007319
TEST=deploy to device and verify *MixerElem controls work

Change-Id: I8da5e5903207c0f7631bca12847b1726d2e54f3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2223112
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Curtis Malainey <cujomalainey@chromium.org>
Commit-Queue: Curtis Malainey <cujomalainey@chromium.org>
4 files changed