[ARM] 3283/1: S3C2400 - defines the number of serial ports

Patch from Lucas Correia Villa Real

This patch defines the number of serial ports on the S3C2400.

Signed-off-by: Lucas Correia Villa Real <lucasvr@gobolinux.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>