ALSA: hda - avoid unneccesary indices on "Headphone Jack" controls

In case there is one "Headphone Jack" and one "Dock Headphone Jack",
one of them will get an index, even though that is not needed.
This patch fixes that issue.

BugLink: https://bugs.launchpad.net/bugs/1060729


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