sunxi: H6: Enable USB for existing boards

So far USB was not enabled for the Allwinner H6 boards, as the PHY
driver was not ready and the clock gates were missing. Since this is now
fixed, let's add the PHY and the OHCI/EHCI drivers to the build, for
all existing H6 boards.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com> # Pine-H64
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>