We want to convert the legacy gpio-keys platform device on BCM47XX boards to use software nodes. To do this properly and allow referencing the GPIO controller by address rather than relying on name-based matching (which is being removed from the gpiolib core), we need to associate the GPIO controller with a software node. Introduce ssb_gpio_swnode, register it, and associate it with the gpio_chip. Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Tested-by: Waldemar Brodkorb <wbx@openadk.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>