[POWERPC] 82xx: Embedded Planet EP8248E support

This board is also resold by Freescale under the names
"QUICCStart MPC8248 Evaluation System" and "CWH-PPC-8248N-VE".

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>