imx: ventana: make number of digital I/O's dynamic

Replace the static list of board-specific digital I/O's with a dynamic list.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/board/gateworks/gw_ventana/gw_ventana.c b/board/gateworks/gw_ventana/gw_ventana.c
index b3390a1..930cec8 100644
--- a/board/gateworks/gw_ventana/gw_ventana.c
+++ b/board/gateworks/gw_ventana/gw_ventana.c
@@ -1209,7 +1209,7 @@
 	}
 
 	/* Configure DIO */
-	for (i = 0; i < gpio_cfg[board_type].num_gpios; i++) {
+	for (i = 0; i < gpio_cfg[board_type].dio_num; i++) {
 		struct dio_cfg *cfg = &gpio_cfg[board_type].dio_cfg[i];
 		char arg[10];