ucm2: Separate the configuration lookups (hw based) from the configuration tree

ucm2: Separate the configuration lookups (hw based) from the configuration tree

Introduce ucm2/conf.d/ tree with symlinks to the real hardware configurations.
In this way, we do not rely to create the configuration paths based on
simple driver / device identification, but we can store the configurations
more logically to make the maintenance (code reuse, multiple changes)
more easy.

This commit keeps the older lookup paths active, but they will be
turned off in the next release.

BugLink: https://github.com/alsa-project/alsa-ucm-conf/pull/70
BugLink: https://github.com/alsa-project/alsa-ucm-conf/pull/76
BugLink: https://github.com/alsa-project/alsa-ucm-conf/pull/78
Signed-off-by: Jaroslav Kysela <perex@perex.cz>