ALSA: hda - Remove obsoleted snd_hda_check_board_config() & co

The helper functions snd_hda_check_board_config() and
snd_hda_check_board_codec_sid_config() are no longer used since the
transition to the generic parser and all quirks have been replaced
with fixups.  Let's kill these dead codes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>