alsa: add card ports and path probe cache

alsa: add card ports and path probe cache

To be able to add ports to all profiles, we need to probe all
profiles at startup. To speed this up, we now have a cache of
probes paths which is owned by the profile set. Since paths
are now owned by the profile set, the path set must now have
a hashmap of paths instead of a linked list.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>