Documentation,ICE1724 driver
Add the support of Chaintech AV-710 to ice1724 driver.
The patch includes the WM-codec initialization fix by
Jaanus Kivistik <jaanus@no.spam.ee>.

Since both AV-710 and AMP Audio2000 have the same SSID, initialize
WM codecs as default for both devices.  In case it breaks Audio2000,
you can pass 'model=amp2000' option to avoid WM codec initialization.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>