crypto/x86_64cpuid.pl: move extended feature detection upwards.

Exteneded feature flags were not pulled on AMD processors, as result a
number of extensions were effectively masked on Ryzen. It should have
been reported for Excavator since it implements AVX2 extension, but
apparently nobody noticed or cared...

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit f8418d87)