pinctrl: pinmux: open-code PINCTRL_FUNCTION_DESC()

This macro is only used in one place and pin function descriptors should
only be created by pinmux core so there's no point in exposing it to
other pinctrl users. Remove the macro and hand-code its functionality.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/20250709-pinctrl-gpio-pinfuncs-v2-1-b6135149c0d9@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: Bartosz Golaszewski

drivers/pinctrl/pinmux.c

@@ -891,7 +891,8 @@ int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 	if (!function)
 		return -ENOMEM;
 
-	*function = PINCTRL_FUNCTION_DESC(name, groups, ngroups, data);
+	function->func = PINCTRL_PINFUNCTION(name, groups, ngroups);
+	function->data = data;
 
 	error = radix_tree_insert(&pctldev->pin_function_tree, selector, function);
 	if (error)

drivers/pinctrl/pinmux.h

@@ -141,13 +141,6 @@ struct function_desc {
 	void *data;
 };
 
-/* Convenient macro to define a generic pin function descriptor */
-#define PINCTRL_FUNCTION_DESC(_name, _grps, _num_grps, _data)	\
-(struct function_desc) {					\
-	.func = PINCTRL_PINFUNCTION(_name, _grps, _num_grps),	\
-	.data = _data,						\
-}
-
 int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev);
 
 const char *