mn10300: allocate serial port UART IDs for on-chip serial ports

Allocate serial port UART type IDs for the MN10300 on-chip serial ports.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>