Maintainers.txt: restore order of OvmfPkg sections
    
    The OvmfPkg subsystem / section headers are currently ordered in
    Maintainers.txt as follows:
    
    > OvmfPkg
    > OvmfPkg: Xen-related modules
    > OvmfPkg: TCG- and TPM2-related modules
    > OvmfPkg: CSM modules
    > OvmfPkg: MptScsi and PVSCSI driver
    
    Restore the following (alphabetical) order between them:
    
    > OvmfPkg
    > OvmfPkg: CSM modules
    > OvmfPkg: MptScsi and PVSCSI driver
    > OvmfPkg: TCG- and TPM2-related modules
    > OvmfPkg: Xen-related modules
    
    Cc: Anthony Perard <anthony.perard@citrix.com>
    Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
    Cc: David Woodhouse <dwmw2@infradead.org>
    Cc: Jordan Justen <jordan.l.justen@intel.com>
    Cc: Julien Grall <julien@xen.org>
    Cc: Liran Alon <liran.alon@oracle.com>
    Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
    Cc: Nikita Leshenko <nikita.leshchenko@oracle.com>
    Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
    Cc: Stefan Berger <stefanb@linux.ibm.com>
    Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2778
    Signed-off-by: Laszlo Ersek <lersek@redhat.com>
    Message-Id: <20200603160627.3594-3-lersek@redhat.com>
    Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
    Reviewed-by: Leif Lindholm <leif@nuviainc.com>