of/base: Fix PowerPC address parsing hack

of/base: Fix PowerPC address parsing hack

commit 746c9e9f92dde2789908e51a354ba90a1962a2eb upstream.

We have a historical hack that treats missing ranges properties as the
equivalent of an empty one. This is needed for ancient PowerMac "bad"
device-trees, and shouldn't be enabled for any other PowerPC platform,
otherwise we get some nasty layout of devices in sysfs or even
duplication when a set of otherwise identically named devices is
created multiple times under a different parent node with no ranges
property.

This fix is needed for the PowerNV i2c busses to be exposed properly
and will fix a number of other embedded cases.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
[bwh: Backported to 3.2: use #ifdef because IS_ENABLED() only works for
 config symbols that are defined on the current architecture]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>