tune-ppc: Update to pass glibc configure option to get cpu specific support
We need --with-cpu based to glibc to get proper support on 603e & e500mc
to pickup proper math libs to deal with sqrt. These core do not
implement the fsqrt[s] instructions that the normal PPC math libs
utilize.
This causes use to not set AVAILTUNES specifically to the sub-arch only
as we arent generically compatiable.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
