Add voice audio card which is used for telephony on gta04 board.
gtm601 codec is UMTS modem with pcm interface which get samples from
microphone and provide data from other party side. Use simple audio card
to describe audio card.
Signed-off-by: Marek Belisko <marek@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>