board: toradex: colibri-imx8x: Remove board_gpio_init

On Colibri iMX8X, the gpio initialization and usage should be handled by
the device tree, not by the colibri-imx8x.c code. Therefore, remove it.

Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
diff --git a/board/toradex/colibri-imx8x/colibri-imx8x.c b/board/toradex/colibri-imx8x/colibri-imx8x.c
index a507d66..3565785 100644
--- a/board/toradex/colibri-imx8x/colibri-imx8x.c
+++ b/board/toradex/colibri-imx8x/colibri-imx8x.c
@@ -93,15 +93,6 @@
 	return 0;
 }
 
-#if IS_ENABLED(CONFIG_DM_GPIO)
-static void board_gpio_init(void)
-{
-	/* TODO */
-}
-#else
-static inline void board_gpio_init(void) {}
-#endif
-
 #if IS_ENABLED(CONFIG_FEC_MXC)
 #include <miiphy.h>
 
@@ -128,8 +119,6 @@
 
 int board_init(void)
 {
-	board_gpio_init();
-
 	if (IS_ENABLED(CONFIG_IMX_SNVS_SEC_SC_AUTO)) {
 		int ret = snvs_security_sc_init();