ARM: S3C2440: Register PCM device on GTA02

The ASoC multi-component patch introduced a new pcm platform device,
which needs to be registered by board files in order for sound to work.
This patch does this for the gta02 board.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>