Check to see if the mkimage tool is part of the cross-compile toolchain.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

--- a/linux-2.6/scripts/mkuboot.sh
+++ b/linux-2.6/scripts/mkuboot.sh
@@ -4,12 +4,15 @@
 # Build U-Boot image when `mkimage' tool is available.
 #
 
-MKIMAGE=$(type -path mkimage)
+MKIMAGE=$(type -path ${CROSS_COMPILE}mkimage)
 
 if [ -z "${MKIMAGE}" ]; then
-	# Doesn't exist
-	echo '"mkimage" command not found - U-Boot images will not be built' >&2
-	exit 0;
+	MKIMAGE=$(type -path mkimage)
+	if [ -z "${MKIMAGE}" ]; then
+		# Doesn't exist
+		echo '"mkimage" command not found - U-Boot images will not be built' >&2
+		exit 0;
+	fi
 fi
 
 # Call "mkimage" to create U-Boot image