xhci: fix nec-usb-xhci properties

xhci: fix nec-usb-xhci properties

Storing properties directly in XHCIPciState.xhci doesn't work,
the object_initialize_child() call in xhci_instance_init() will
overwrite them.

This changes the defaults for some properties, which in turn breaks
live migration and possibly other things as well.

So add XHCINecState, store properties there, copy them over on
instance init.

Fixes: 8ddab8dd3d81 ("usb/hcd-xhci: Split pci wrapper for xhci base model")
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20201112103741.2335-1-kraxel@redhat.com