Currently the only mpc8544ds-ism that is factored out is
toplevel compatible and model.  In the future the generic e500
code is expected to become more generic.
Signed-off-by: NScott Wood <scottwood@freescale.com>
[agraf: conditionalize on CONFIG_FDT]
Signed-off-by: NAlexander Graf <agraf@suse.de>