ASoC: Samsung: Rename AC97 platform device

Call the AC97 controller devices found in S3C, S5P and newer
SoCs as 'samsung-ac97' rather than 's3c-ac97'.

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