[PowerPC64] Skip using getauxval() when it is not available
This patch skips using getauxval() function to detect CPU features when glibc version is older than 2.16 where getauxval() has not been added yet.
This patch skips using getauxval() function to detect CPU features when glibc version is older than 2.16 where getauxval() has not been added yet.