[ARM] 4220/1: S3C24XX: DMA system initialised from sysdev

This patch gets the DMA system for the S3C24XX
ready for the S3C2443, which requires 6 dma channels
at a different stride, and different base IRQ.

The DMA system is now initialised from the same
drivers which apply the DMA mappings, as well
as removing the DMA sysdev intialisation out of
the main init code (which is now being called
from a sysdev probe, so cannot add a new sysdev)

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