Due to differences in /proc/cpuinfo the parsing of the cpu data is
different between architectures. On PPC /proc/cpuinfo looks like this:

[original formatting with tabs]

processor    : 0
cpu          : PPC970MP, altivec supported
clock        : 2297.700000MHz
revision     : 1.1 (pvr 0044 0101)

processor    : 1
cpu          : PPC970MP, altivec supported
clock        : 2297.700000MHz
revision     : 1.1 (pvr 0044 0101)

[..]

timebase     : 14318000
platform     : pSeries
model        : IBM,8844-AC1
machine      : CHRP IBM,8844-AC1

The patch adapts the parsing of the data found in /proc/cpuinfo.

/sys/devices/system/cpu/cpuX/topology/physical_package_id also
always returns -1. Check for it on ppc and make it '0' if found negative.