86xx: Convert sbc8641d to use libfdt.

86xx: Convert sbc8641d to use libfdt.

This is the proper fix for a missing closing brace in the function
ft_cpu_setup() noticed by joe.hamman <at> embeddedspecialties.com.
The ft_cpu_setup() function in mpc8641hpcn.c should have been
removed earlier as it was under the obsolete CONFIG_OF_FLAT_TREE,
but was missed.  Only, the sbc8641d was nominally still using it.
It all got ripped out, and the funcality that was in ft_board_setup()
was refactored to remove the CPU portions into the new file
cpu/mpc86xx/fdt.c instead.  Make sbc8641d use this now.

Based loosely on an original patch from joe.hamman@embeddedspecialties.com

Signed-off-by: Jon Loeliger <jdl@freescale.com>