update alsa ucm2 / pulseaudio config to 5.15+ linux kernels

newer linux kernels include that change: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=907f0a3051869a61499905377212500155bd28ec which removes the Librem_5 and Librem_5_Devkit card names and audio doesn't work anymore with this.

To clarify: in our tree, we revert the above commit in order to stay compatible. We want to remove the revert, at the same time we have a working config here, though.

renaming the Librem_5 directory to Librem 5 in /usr/share/alsa/ucm2/ makes system sound work again, but not for the modem (calls don't work at all).

in order to use the mainline kernel we need to adjust the audio config.