usb: host: xhci: Make U_BOOT_DRIVER entries unique

usb: host: xhci: Make U_BOOT_DRIVER entries unique

All instances of the U_BOOT_DRIVER must use a unique name or they will
lead to link time failures due to name space conflicts when both are
present. Most of the XHCI drivers follow pattern of xhci_xxx in their
name, but a few used "usb_xhci". Change these to follow the pattern of
the rest of the XHCI glue drivers.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>