leds: Provide stubs for when CLASS_LED & NEW_LEDS are disabled

Provide stubs for devm_led_classdev_register_ext() and
led_init_default_state_get() so that LED drivers embedded within other
drivers such as PHYs and Ethernet switches still build when LEDS_CLASS
or NEW_LEDS are disabled. This also helps with Kconfig dependencies,
which are somewhat hairy for phylib and mdio and only get worse when
adding a dependency on LED_CLASS.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/leds.h

@@ -82,7 +82,15 @@ struct led_init_data {
 	bool devname_mandatory;
 };
 
+#if IS_ENABLED(CONFIG_NEW_LEDS)
 enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode);
+#else
+static inline enum led_default_state
+led_init_default_state_get(struct fwnode_handle *fwnode)
+{
+	return LEDS_DEFSTATE_OFF;
+}
+#endif
 
 struct led_hw_trigger_type {
 	int dummy;
@@ -217,9 +225,19 @@ static inline int led_classdev_register(struct device *parent,
 	return led_classdev_register_ext(parent, led_cdev, NULL);
 }
 
+#if IS_ENABLED(CONFIG_LEDS_CLASS)
 int devm_led_classdev_register_ext(struct device *parent,
 					  struct led_classdev *led_cdev,
 					  struct led_init_data *init_data);
+#else
+static inline int
+devm_led_classdev_register_ext(struct device *parent,
+			       struct led_classdev *led_cdev,
+			       struct led_init_data *init_data)
+{
+	return 0;
+}
+#endif
 
 static inline int devm_led_classdev_register(struct device *parent,
 					     struct led_classdev *led_cdev)