OvmfPkg: SmmCpuFeaturesLib: customize state save map format
    
    This adjusts the previously introduced state save map access functions, to
    account for QEMU and KVM's 64-bit state save map following the AMD spec
    rather than the Intel one.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    [lersek@redhat.com: reflow commit message, convert patch to CRLF]
    Cc: Paolo Bonzini <pbonzini@redhat.com>
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Laszlo Ersek <lersek@redhat.com>
    Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>