hw/pci-host/i440fx: Move i440fx_realize() into PCII440FXState section

hw/pci-host/i440fx: Move i440fx_realize() into PCII440FXState section

i440fx_realize() realizes the PCI device inside the host bridge
(PCII440FXState), but is implemented between i440fx_pcihost_realize() and
i440fx_init() which deal with the host bridge itself (I440FXState). Since we
want to append i440fx_init() to i440fx_pcihost_realize() later let's move
i440fx_realize() out of the way.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230630073720.21297-12-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>