board: stm32mp1: update the gpio hog support

This patch updates the current gpio hog implementation and uses
the new API gpio_hog_probe_all(), activated with CONFIG_GPIO_HOG.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index 4cea5bd..c5c89d2 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -670,17 +670,11 @@
 /* board dependent setup after realloc */
 int board_init(void)
 {
-	struct udevice *dev;
-
 	/* address of boot parameters */
 	gd->bd->bi_boot_params = STM32_DDR_BASE + 0x100;
 
-	/* probe all PINCTRL for hog */
-	for (uclass_first_device(UCLASS_PINCTRL, &dev);
-	     dev;
-	     uclass_next_device(&dev)) {
-		pr_debug("probe pincontrol = %s\n", dev->name);
-	}
+	if (CONFIG_IS_ENABLED(DM_GPIO_HOG))
+		gpio_hog_probe_all();
 
 	board_key_check();