dependencies: check for >= make 3.81

Reported by Andrew Dyer <amdyer@gmail.com> and
Lionel Landwerlin <lionel.landwerlin@openwide.fr>.

Seems like make 3.80 has problems with our Makefile.autotools.in
infrastructure.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/dependencies/dependencies.sh

@@ -165,8 +165,8 @@ if [ -z "$MAKE_VERSION" ] ; then
 fi;
 MAKE_MAJOR=$(echo $MAKE_VERSION | $XSED -e "s/\..*//g")
 MAKE_MINOR=$(echo $MAKE_VERSION | $XSED -e "s/^$MAKE_MAJOR\.//g" -e "s/\..*//g" -e "s/[a-zA-Z].*//g")
-if [ $MAKE_MAJOR -lt 3 ] || [ $MAKE_MAJOR -eq 3 -a $MAKE_MINOR -lt 80 ] ; then
-	echo "You have make '$MAKE_VERSION' installed.  GNU make >=3.80 is required"
+if [ $MAKE_MAJOR -lt 3 ] || [ $MAKE_MAJOR -eq 3 -a $MAKE_MINOR -lt 81 ] ; then
+	echo "You have make '$MAKE_VERSION' installed.  GNU make >=3.81 is required"
 	exit 1;
 fi;
 echo "GNU make version '$MAKE_VERSION':			Ok"