gpio: Get rid of legacy header

A bunch of core gpiolib files still include the <linux/gpio.h>
legacy API header for no good reason. After this only the
gpiolib-legacy.c file includes it, which is fine.

The sysfs ABI code has a pointless wrapper function around
gpio_to_desc() we can just loose.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-acpi.c

@@ -11,7 +11,6 @@
  */
 
 #include <linux/errno.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/machine.h>

drivers/gpio/gpiolib-sysfs.c

@@ -2,7 +2,6 @@
 #include <linux/mutex.h>
 #include <linux/device.h>
 #include <linux/sysfs.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
@@ -444,11 +443,6 @@ static struct attribute *gpiochip_attrs[] = {
 };
 ATTRIBUTE_GROUPS(gpiochip);
 
-static struct gpio_desc *gpio_to_valid_desc(int gpio)
-{
-	return gpio_is_valid(gpio) ? gpio_to_desc(gpio) : NULL;
-}
-
 /*
  * /sys/class/gpio/export ... write-only
  *	integer N ... number of GPIO to export (full access)
@@ -467,7 +461,7 @@ static ssize_t export_store(struct class *class,
 	if (status < 0)
 		goto done;
 
-	desc = gpio_to_valid_desc(gpio);
+	desc = gpio_to_desc(gpio);
 	/* reject invalid GPIOs */
 	if (!desc) {
 		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
@@ -514,7 +508,7 @@ static ssize_t unexport_store(struct class *class,
 	if (status < 0)
 		goto done;
 
-	desc = gpio_to_valid_desc(gpio);
+	desc = gpio_to_desc(gpio);
 	/* reject bogus commands (gpio_unexport ignores them) */
 	if (!desc) {
 		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);