armv8: ls1028a: enable workaround for USB erratum A-008997

Enable workaround for USB erratum A-008997. Here PCSTXSWINGFULL
registers has been moved to DSCR as compared to other Layerscape SoCs
where it was in SCFG.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>