Ticket 49228 - Fix SSE4.2 detection.
    
    Bug Description:  We incorrectly detect sse4.2 on some platforms.
    
    Fix Description:  Instead of detecting this, we allow GCC to define
    the feature flag when possible. At this time, we only use sse4.2
    for verification during tests. RPMS build with -mtune=generic, which
    will disable sse4.2, so anyone who wants "fast" test execution
    (ie a developer) should set -march=native in their cflags.
    
    https://pagure.io/389-ds-base/issue/49228
    
    Author: wibrown
    
    Review by: mreynolds
    
    Signed-off-by: Mark Reynolds <mreynolds@redhat.com>