Kernel 6.19 will get rid of of_node_to_fwnode(). Switch to its
successor of_fwnode_handle() that is already available in 6.18.
This will simplify a future kernel upgrade.
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/23434
Signed-off-by: Robert Marko <robimarko@gmail.com>