dts: bindings: can: remove #address-cells and #size-cells

Remove the requirement for specifying #address-cells and #size-cells
properties for CAN controller devicetree nodes.

CAN controllers do not have a common concept of devicetree child nodes
and thus have no need for these properties. This is in line with
upstream Linux kernel devicetree bindings.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>