imx: mkimage: avoid stop CI when required files not exists

Introduce a new script to check whether file exists and
use that check in Makefile to avoid break CI system.

The script return 1 when the required files not exists, return 0
when files exists. The script will ignore check to u-boot-dtb.bin,
because if there is something wrong to generate u-boot-dtb.bin,
there must be some code error.

Signed-off-by: Peng Fan <peng.fan@nxp.com>

tools/imx_cntr_image.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# script to check whether the file exists in imximage.cfg for i.MX8
+#
+# usage: $0 <imximage.cfg>
+
+file=$1
+
+blobs=`awk '/^APPEND/ {print $2} /^IMAGE/ || /^DATA/ {print $3}' $file`
+for f in $blobs; do
+	tmp=$srctree/$f
+	if [ $f == "u-boot-dtb.bin" ]; then
+		continue
+	fi
+
+	if [ -f $f ]; then
+		continue
+	fi
+
+	if [ ! -f $tmp ]; then
+		echo "WARNING '$tmp' not found, resulting binary is not-functional" >&2
+		exit 1
+	fi
+
+	sed -in "s;$f;$tmp;" $file
+done
+
+exit 0