USB-Audio: Add support for Solid State Labs SSL 2+

alsa-project/alsa-ucm-conf pull request #429 was opened from kescherCode:

This adds support for the [Solid State Labs SSL 2+](https://www.solidstatelogic.com/products/ssl2-plus).

Note that this *is* a distinct device to the SSL 2, support for which was added in #377. The most notable difference is that this device has two additional outputs (physically four, but two of those are mirrored).

Request URL : https://github.com/alsa-project/alsa-ucm-conf/pull/429 Patch URL : https://github.com/alsa-project/alsa-ucm-conf/pull/429.patch Repository URL: https://github.com/alsa-project/alsa-ucm-conf