ALSA: hda: hdmi: Hint matching between input devices and pcm devices

Since modern HDMI cards often have more than one output pin and thus
input device, we need to know which one has actually been plugged in.

This patch adds a name hint that indicates which PCM device is connected
to which pin.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>