gpiolib: Deduplicate forward declarations in consumer.h

The struct fwnode_handle pointer is used in both branches of ifdeffery,
no need to have a copy of the same in each of them, just make it global.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

include/linux/gpio/consumer.h

@@ -8,6 +8,7 @@
 #include <linux/err.h>
 
 struct device;
+struct fwnode_handle;
 struct gpio_desc;
 struct gpio_array;
 
@@ -171,9 +172,6 @@ int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name);
 struct gpio_desc *gpio_to_desc(unsigned gpio);
 int desc_to_gpio(const struct gpio_desc *desc);
 
-/* Child properties interface */
-struct fwnode_handle;
-
 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
 					 const char *con_id, int index,
 					 enum gpiod_flags flags,
@@ -546,9 +544,6 @@ static inline int desc_to_gpio(const struct gpio_desc *desc)
 	return -EINVAL;
 }
 
-/* Child properties interface */
-struct fwnode_handle;
-
 static inline
 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
 					 const char *con_id, int index,