gpio: of: Make of_gpio_simple_xlate() private

Since commit 9a95e8d2 ("gpio: remove etraxfs driver"), there are
no more users of of_gpio_simple_xlate() outside gpiolib-of.c.
All GPIO drivers that need it now rely on of_gpiochip_add() setting it
up as the default translate function.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20190906084539.21838-3-geert+renesas@glider.beSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-of.c

@@ -637,8 +637,9 @@ static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
  * GPIO chips. This function performs only one sanity check: whether GPIO
  * is less than ngpios (that is specified in the gpio_chip).
  */
-int of_gpio_simple_xlate(struct gpio_chip *gc,
-			 const struct of_phandle_args *gpiospec, u32 *flags)
+static int of_gpio_simple_xlate(struct gpio_chip *gc,
+				const struct of_phandle_args *gpiospec,
+				u32 *flags)
 {
 	/*
 	 * We're discouraging gpio_cells < 2, since that way you'll have to
@@ -662,7 +663,6 @@ int of_gpio_simple_xlate(struct gpio_chip *gc,
 
 	return gpiospec->args[0];
 }
-EXPORT_SYMBOL(of_gpio_simple_xlate);
 
 /**
  * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)

include/linux/of_gpio.h

@@ -61,10 +61,6 @@ static inline int of_mm_gpiochip_add(struct device_node *np,
 }
 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
 
-extern int of_gpio_simple_xlate(struct gpio_chip *gc,
-				const struct of_phandle_args *gpiospec,
-				u32 *flags);
-
 #else /* CONFIG_OF_GPIO */
 
 /* Drivers may not strictly depend on the GPIO support, so let them link. */
@@ -77,13 +73,6 @@ static inline int of_get_named_gpio_flags(struct device_node *np,
 	return -ENOSYS;
 }
 
-static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
-				       const struct of_phandle_args *gpiospec,
-				       u32 *flags)
-{
-	return -ENOSYS;
-}
-
 #endif /* CONFIG_OF_GPIO */
 
 /**