Add support for the MPC837xERDB

MPC837xERDB board support includes:
* DDR2 330MHz hardcoded (soldered on the board)
* Local Bus NOR Flash
* I2C, UART and RTC
* eTSEC RGMII (TSEC0 - RTL8211B with MII;
*	       TSEC1 - VSC7385 local bus, hardcoded, requires seperate firmware
*		       load)

Signed-off-by: Kevin Lam <kevin.lam@freescale.com>
Signed-off-by: Joe D'Abbraccio <joe.d'abbraccio@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>