m68knommu: platform setup for 5206e ColdFire parts

Switch to platform style configuration for 5206e ColdFire parts.
Initial support is for the UARTs. DMA support is moved to common code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>