drm/i915/audio: Remove CL/BLC audio stuff

We don't use the audio code on crestline (CL) since it doesn't
support native HDMI output, and SDVO has it's own way of doing
audio.

And Bearlake-C (BLC) doesn't even exist in the real world, so
no point it trying to deal with it.

Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026170150.2654-4-ville.syrjala@linux.intel.com