ASoC: Set more meaningful name for SMDK64xx WM8580 audio

Since the SMDK64xx boards have two audio subsystems using the board
name as the card name by itself isn't so user friendly as it might
be.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>