[POWERPC] Fix MPC8360EMDS PB board support

MPC8360EMDS PB support is broken as some code was missing
in last submission.  This patch adds missing code and makes
MPC8360EMDS PB support working.

Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>