of: property: make #.*-cells optional for simple props

Sometimes, future bindings for phandles will get additional arguments.
Thus the target node of the phandle will need a new #.*-cells property.
To be backwards compatible, this needs to be optional.

Prepare the DEFINE_SIMPLE_PROPS() to handle the cells name as optional.
Signed-off-by: Michael Walle <michael@walle.cc>
Tested-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-11-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/of/property.c

@@ -1202,8 +1202,8 @@ static struct device_node *parse_prop_cells(struct device_node *np,
 	if (strcmp(prop_name, list_name))
 		return NULL;
 
-	if (of_parse_phandle_with_args(np, list_name, cells_name, index,
-				       &sup_args))
+	if (__of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
+					 &sup_args))
 		return NULL;
 
 	return sup_args.np;