mpc832x: add support for the mpc8321 based suvd3 board

- serial console on UART1
- Ethernet RMII over UCC4
- PHY SMSC LAN8700
- 64MB Flash
- 128 MB DDR2 RAM
- I2C
- bootcount

This board is similiar to the kmeter1 (8360) board,
so common config options are extracted into the
include/configs/km83xx-common.h file.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
cc: Kim Phillips <kim.phillips@freescale.com>
cc: Holger Brunck <holger.brunck@keymile.com>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>