pinctrl: pinctrl_stm32: Update pinmux_mode definition

pinmux_mode[] is linked to gpio_function[] defined in gpio-uclass.c
So reuse the same gpio_func_t enum value

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/drivers/pinctrl/pinctrl_stm32.c b/drivers/pinctrl/pinctrl_stm32.c
index 5729799..5d8e156 100644
--- a/drivers/pinctrl/pinctrl_stm32.c
+++ b/drivers/pinctrl/pinctrl_stm32.c
@@ -42,13 +42,12 @@
 #ifndef CONFIG_SPL_BUILD
 
 static char pin_name[PINNAME_SIZE];
-#define PINMUX_MODE_COUNT		5
-static const char * const pinmux_mode[PINMUX_MODE_COUNT] = {
-	"gpio input",
-	"gpio output",
-	"analog",
-	"unknown",
-	"alt function",
+static const char * const pinmux_mode[GPIOF_COUNT] = {
+	[GPIOF_INPUT] = "gpio input",
+	[GPIOF_OUTPUT] = "gpio output",
+	[GPIOF_UNUSED] = "analog",
+	[GPIOF_UNKNOWN] = "unknown",
+	[GPIOF_FUNC] = "alt function",
 };
 
 static const char * const pinmux_bias[] = {