Fix Makefile.am altivec logic
Fix Makefile.am altivec logic

Besides SPE (FSL e500v? cores) there are other powerpc processors
that don't support altivec instructions so only enable them when it's
100% sure that the target has it.

Signed-off-by: Gustavo Zacarias <beac5f8171fcde5e2ec734cc5d25d03e7362e8de@zacarias.com.ar>
Signed-off-by: Erik de Castro Lopo <1586a8e151fb6d548e7a343b9bcdfea42e83ffc0@mega-nerd.com>

fredericgermain/flac,waitman/flac,waitman/flac,waitman/flac,waitman/flac,waitman/flac,fredericgermain/flac,fredericgermain/flac,fredericgermain/flac