powerpc: Make chip-id information available to userspace

powerpc: Make chip-id information available to userspace

So far "/sys/devices/system/cpu/cpuX/topology/physical_package_id"
was always default (-1) on ppc64 architecture.

Now, some systems have an ibm,chip-id property in the cpu nodes in
the device tree. On these systems, we now use this information to
display physical_package_id.

Signed-off-by: Vasant Hegde <[email protected]>
Signed-off-by: Shivaprasad G Bhat <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>