ALSA: hda - Add initial support for Thinkpad T410s HDA codec

attached please find a patch that adds support for at least the T410s
HDA codec.  Most likely it will also add support for the T410 and T510
based models.

The patch was derived from Ideapad support.  Support for the laptop's and
docking-station output connectors as well as the docking-station microphone
connector and the laptops internal devices has been tested.  Since it has been
developed without a data-sheet available, support for digital outputs and the
laptop's microphone input may well be incorrect.

Microphone mute functionality is not included:
The microphone mute button seems to be reported through thinkpad_acpi key
0000101b.  The mute button LED seems to be wired to thinkpad_acpi led
number 15.

Signed-off-by: Jens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>