reset: convert reset core to using firmware nodes

reset: convert reset core to using firmware nodes

With everything else now in place, we can convert the remaining parts of
the reset subsystem to becoming fwnode-agnostic - meaning it will work
with all kinds of firmware nodes, not only devicetree.

To that end: extend struct reset_controller_dev with fields taking
information relevant for using firmware nodes (which mirrors what we
already do for OF-nodes) and limit using of_ APIs only to where it's
absolutely necessary (mostly around the of_xlate callback).

For backward compatibility of existing drivers we still support OF-nodes
but firmware nodes become the preferred method.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>