usb: xhci-pci: Drop non-DM version of xhci-pci driver

As there is no board that currently uses xhci-pci driver without DM
USB, drop its support and leave only DM support.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2 files changed