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