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 firstname.lastname@example.org Signed-off-by: Jon Loeliger <email@example.com>