leds: Add missing includes and forward declarations in leds.h

Add missing includes and forward declarations to leds.h. While at it,
replace headers by forward declarations and vise versa.

Signed-off-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

include/linux/leds.h

···
 
 #include <dt-bindings/leds/common.h>
 #include <linux/device.h>
-#include <linux/kernfs.h>
-#include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
+#include <linux/types.h>
 #include <linux/workqueue.h>
 
-struct device;
-struct led_pattern;
+struct attribute_group;
 struct device_node;
+struct fwnode_handle;
+struct gpio_desc;
+struct kernfs_node;
+struct led_pattern;
+struct platform_device;
+
 /*
  * LED Core
  */
···
 	const char	*label;
 };
 
-struct gpio_desc;
 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 				unsigned long *delay_on,
 				unsigned long *delay_off);