dt-bindings: wireless: silabs,wfx: Use wireless-controller.yaml

Instead listing local-mac-address and mac-address properties, reference
wireless-controller.yaml schema. The schema brings in constraints for the
property checked during `make dtbs_check`.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20250324-dt-bindings-network-class-v5-4-f5c3fe00e8f0@ixit.cz


Signed-off-by: Johannes Berg <johannes.berg@intel.com>