[ALSA] Add support for Sony Vaio AR 11B

This patch adds automatic detection for Sigmatel ID 7664,
the sound chip in Sony Vaio AR 11B (european name).
- patch_stac7661 becomes patch_stac766x
- .id = 0x83847664 is added

Signed-off-by: Guillaume Munch <diabo@free.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>