board: engicam: Remove bogus check for mmc for imx6ul isiot

imx6ul-isiot-mmc.dts was removed in uboot version v2018.03 and from then
onwards IMX6UL isiot uses imx6ul-isiot-emmc.dts for mmc, so remove
unnecessary check for mmc.

Signed-off-by: Shyam Saini <shyam.saini@amarulasolutions.com>
diff --git a/board/engicam/common/board.c b/board/engicam/common/board.c
index 7486f0a..567b9f6 100644
--- a/board/engicam/common/board.c
+++ b/board/engicam/common/board.c
@@ -53,8 +53,6 @@
 			env_set("fdt_file", "imx6dl-icore-rqs.dtb");
 	} else if (!strcmp(cmp_dtb, "imx6ul-geam"))
 		env_set("fdt_file", "imx6ul-geam.dtb");
-	else if (!strcmp(cmp_dtb, "imx6ul-isiot-mmc"))
-		env_set("fdt_file", "imx6ul-isiot-emmc.dtb");
 	else if (!strcmp(cmp_dtb, "imx6ul-isiot-emmc"))
 		env_set("fdt_file", "imx6ul-isiot-emmc.dtb");
 	else if (!strcmp(cmp_dtb, "imx6ul-isiot-nand"))