Makefile: install libraries /usr/lib64 on x86_64
Makefile: install libraries /usr/lib64 on x86_64

When building on a 64-bit machine, we'll expect to find the libraries
in /usr/lib64. With this, the openSUSE Build Service can build
packages for Fedora, CentOS, and RedHat.

zerovm/validator,zerovm/validator,zerovm/validator,zerovm/validator