gpiolib: Ensure struct gpio is always defined

Currently struct gpio is only defined when using gpiolib which makes the
stub gpio_request_array() much less useful in drivers than is ideal as
they can't work with struct gpio.  Since there are no other definitions
in kernel instead make the define always available no matter if gpiolib
is selectable or selected, ensuring that drivers can always use the
type.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d494001..dbb2832 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -41,6 +41,7 @@
 }
 
 struct device;
+struct gpio;
 struct seq_file;
 struct module;
 struct device_node;
@@ -170,18 +171,6 @@
 
 extern int __gpio_to_irq(unsigned gpio);
 
-/**
- * struct gpio - a structure describing a GPIO with configuration
- * @gpio:	the GPIO number
- * @flags:	GPIO configuration as specified by GPIOF_*
- * @label:	a literal description string of this GPIO
- */
-struct gpio {
-	unsigned	gpio;
-	unsigned long	flags;
-	const char	*label;
-};
-
 extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 extern int gpio_request_array(const struct gpio *array, size_t num);
 extern void gpio_free_array(const struct gpio *array, size_t num);