power: supply: all: switch psy_cfg from of_node to fwnode

When registering a power-supply device, either a of_node or the more
recent fwnode can be supplied. Since fwnode can also contain an of_node,
let's try to get rid of it.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20250225-psy-core-convert-to-fwnode-v1-4-d5e4369936bb@collabora.com


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>