nuc.conf: mask out meta-nuc hdmi hack

The hdmi init script and asound.conf provided by meta-nuc serve no useful
purpose on a modern system with Pulseaudio.
pulseaudio: provide specific pa config for the nuc

For some reason the HDMI card in the nuc is not detected using udev, for
now statically load pa alsa module for both of devices the HDMI card
provides.

The other consequence of the udev detection not working for this card is
that we only get audio on the HDMI1 output; needs a proper fix.