powerpc adjust oprofile_cpu_type version 3

Oprofile is changing the naming it is using for the compatibility modes.
Instead of having compat-power<x>, oprofile will go to family naming
convention and use ibm-compat-v<x>.  Currently only ibm-compat-v1 will
be defined.
The notion of compatibility events just started with POWER6. So there is
no way that any other tool could exist that is using these
oprofile_cpu_type strings we want to change.

Signed-off-by: Mike Wolf <mjw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>