Move a bunch of defines which might be needed outside core xhci
code to that place.  Add XHCI_ prefixes to avoid name clashes.
No functional change.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Message-id: 20201020074844.5304-3-kraxel@redhat.com