drivers/gpio/nomadik: move dummy nmk_gpio_dbg_show_one() to header

When `CONFIG_DEBUG_FS` is disabled, nmk_gpio_dbg_show_one() is an
empty dummy function; this however triggers a `-Wmissing-prototypes`
warning and later a linker error because the function is also used by
drivers/pinctrl/nomadik/pinctrl-nomadik.c, therefore it needs to be
non-static.

To allow both sources to access this dummy function, this patch moves
it to the header, adding the `#ifdef CONFIG_DEBUG_FS` there as well.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Link: https://lore.kernel.org/r/20240311133223.3429428-1-max.kellermann@ionos.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: MaxKellermann

drivers/gpio/gpio-nomadik.c

@@ -486,14 +486,6 @@ static void nmk_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 #else
 
-static inline void nmk_gpio_dbg_show_one(struct seq_file *s,
-					 struct pinctrl_dev *pctldev,
-					 struct gpio_chip *chip,
-					 unsigned int offset,
-					 unsigned int gpio)
-{
-}
-
 #define nmk_gpio_dbg_show	NULL
 
 #endif

include/linux/gpio/gpio-nomadik.h

@@ -253,6 +253,8 @@ nmk_pinctrl_db8540_init(const struct nmk_pinctrl_soc_data **soc)
 
 struct platform_device;
 
+#ifdef CONFIG_DEBUG_FS
+
 /*
  * Symbols declared in gpio-nomadik used by pinctrl-nomadik. If pinctrl-nomadik
  * is enabled, then gpio-nomadik is enabled as well; the reverse if not always
@@ -261,6 +263,19 @@ struct platform_device;
 void nmk_gpio_dbg_show_one(struct seq_file *s, struct pinctrl_dev *pctldev,
 			   struct gpio_chip *chip, unsigned int offset,
 			   unsigned int gpio);
+
+#else
+
+static inline void nmk_gpio_dbg_show_one(struct seq_file *s,
+					 struct pinctrl_dev *pctldev,
+					 struct gpio_chip *chip,
+					 unsigned int offset,
+					 unsigned int gpio)
+{
+}
+
+#endif
+
 void __nmk_gpio_make_output(struct nmk_gpio_chip *nmk_chip,
 			    unsigned int offset, int val);
 void __nmk_gpio_set_slpm(struct nmk_gpio_chip *nmk_chip, unsigned int offset,