of: property: Improve finding the supplier of a remote-endpoint property

After commit 4a03282 ("of: property: Simplify of_link_to_phandle()"),
remote-endpoint properties created a fwnode link from the consumer device
to the supplier endpoint. This is a tiny bit inefficient (not buggy) when
trying to create device links or detecting cycles. So, improve this the
same way we improved finding the consumer of a remote-endpoint property.

Fixes: 4a03282 ("of: property: Simplify of_link_to_phandle()")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20240207011803.2637531-3-saravanak@google.com
Signed-off-by: Rob Herring <robh@kernel.org>

Author: Saravana Kannan

drivers/of/property.c

@@ -1232,7 +1232,6 @@ DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
 DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
 DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
 DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
-DEFINE_SIMPLE_PROP(remote_endpoint, "remote-endpoint", NULL)
 DEFINE_SIMPLE_PROP(pwms, "pwms", "#pwm-cells")
 DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
 DEFINE_SIMPLE_PROP(leds, "leds", NULL)
@@ -1298,6 +1297,17 @@ static struct device_node *parse_interrupts(struct device_node *np,
 	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
 }
 
+static struct device_node *parse_remote_endpoint(struct device_node *np,
+						 const char *prop_name,
+						 int index)
+{
+	/* Return NULL for index > 0 to signify end of remote-endpoints. */
+	if (!index || strcmp(prop_name, "remote-endpoint"))
+		return NULL;
+
+	return of_graph_get_remote_port_parent(np);
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },