driver core: platform: allow attaching software nodes when creating devices

driver core: platform: allow attaching software nodes when creating devices

Extend platform_device_info structure with an optional pointer to a
software node to be used as a secondary firmware node for the device
being created. If software node has not been registered yet it will be
automatically registered.

This reduces boilerplate needed when switching legacy board code to
static device properties/GPIO references.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260214025246.2095239-3-dmitry.torokhov@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>