Some SoCs have a ranges property set in their device trees. This can

Some SoCs have a ranges property set in their device trees.  This can
be used to translate one memory address to another.  Currently we just
pass the child's memory address to bus space map.  If one of the parent
busses implements a ranges property, the child's address property is
not the real address.  This change hooks up a bus space map function
that is aware of the ranges property and translates the addresses if
needed.

ok kettenis@
looks fine jsg@