power: supply: core: remove of_node from power_supply_config

All drivers have been migrated from .of_node to .fwnode,
so let's kill the former.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20250430-psy-core-convert-to-fwnode-v2-2-f9643b958677@collabora.com


Reviewed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>