[ARM] 4219/1: S3C2443: DMA source definitions

Defines for the S3C2443 DMA source selection,
and update the maximum channels to 6 if the S3C2443
is selected.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>