hw/pci-bridge/cxl_upstream: Provide x-speed and x-width properties.

hw/pci-bridge/cxl_upstream: Provide x-speed and x-width properties.

Copied from gen_pcie_root_port.c
Drop the previous code that ensured a valid value in s->width, s->speed
as now a default is provided so this will always be set.

Note this changes the default settings but it is unlikely to have a negative
effect on software as will only affect ports with now downstream device.
All other ports will use the settings from that device.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240916173518.1843023-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>