ALSA: hda - Add a sanity check of pin / port mapping on i915 HDMI/DP

There is an implicit rule to map between pin NID and port number on
Intel HDMI/DP codec: the mapping is fixed only for NID 0x05, 0x06 and
0x07.  For avoiding the possible memory corruption, add a sanity check
for the NID value and splat WARN_ON() for invalid accesses.

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