Update to 1.3.0 release candidate 2
    
    This commit updates tpm2-tss to version 1.3.0-rc2. It also does some
    cleanups to the package such as using the latest URL for the project
    repository, removing an unneeded global prefix and remove a compiler
    flag that's no longer needed.
    
    resolves: rhbz#1508870
    
    Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>