of: Fix address decoding on Bimini and js2x machines

of: Fix address decoding on Bimini and js2x machines

 Commit:

  e38c0a1fbc5803cbacdaac0557c70ac8ca5152e7
  of/address: Handle #address-cells > 2 specially

broke real time clock access on Bimini, js2x, and similar powerpc
machines using the "maple" platform. That code was indirectly relying
on the old (broken) behaviour of the translation for the hypertransport
to ISA bridge.

This fixes it by treating hypertransport as a PCI bus

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>