software node: Switch property entry test to a new API

Switch property entry test to use software_node_register_node_group() API.
The current one is going to be removed soon.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Daniel Scally <dan.scally@ideasonboard.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20221228094922.84119-4-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>