83xx: add support for ve8313 board

This patch add support for the ve8313 board based on
Freescale MPC8313 CPU.

- serial console on UART 1
- 128 MB DDR RAM
- 32 MB NOR Flash
- 16 MB NAND Flash
- Ethernet MII Mode over on TSEC0
- micrel ksz804 phy
- Hardware WDT MAX824

changes since v1
- Environment size = sector size
- use red. environment
- add comments from Kim Phillips
  - add MAKEALL, MAINTAINERS entry
  - Codingstyle issues fixed
  - inserted original Copyrights
  - PCI subsys vendor ID changed from 0x1057 (Motorola)
    to 0x1957 (Freescale)

changes since v2
- add comments from Wolfgang Denk
  - fix Codingstyle and some comments
  - reworked WDT reset (just toggling the WD_TRIG pin)
  - Environment size now 16KiB
  - fixed RAMBOOT version
  - fixed CONFIG_SYS_LOAD_ADDR
  - renamed CONFIG_TSEC1_NAME to TSEC1

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>