engicam: Set fdt_file env during run-time

Set fdt_file env variable during board_late_init

Cc: Stefano Babic <sbabic@denx.de>
Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/board/engicam/isiotmx6ul/isiotmx6ul.c b/board/engicam/isiotmx6ul/isiotmx6ul.c
index 29a137d..5d1c693 100644
--- a/board/engicam/isiotmx6ul/isiotmx6ul.c
+++ b/board/engicam/isiotmx6ul/isiotmx6ul.c
@@ -149,6 +149,14 @@
 		break;
 	}
 
+	if (is_mx6ul()) {
+#ifdef CONFIG_ENV_IS_IN_MMC
+		setenv("fdt_file", "imx6ul-isiot-emmc.dtb");
+#else
+		setenv("fdt_file", "imx6ul-isiot-nand.dtb");
+#endif
+	}
+
 	return 0;
 }