spapr: SPLPAR Characteristics

spapr: SPLPAR Characteristics

Improve the SPLPAR Characteristics information:

    Add MaxPlatProcs: set to max_cpus, the maximum CPUs that could be
    addded to the system.
    Add DesMem: set to the initial memory of the system.
    Add DesProcs: set to smp_cpus, the inital number of CPUs in the
    system.

These tokens and values are specified by PAPR.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>