[POWERPC] Add missing pmc_type fields in cpu_table

A number of cpu_table entries were missing the pmc_type field,
which means that the sysfs entries for the performance monitor
counters don't get created.  This adds them.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>