oe-setup-builddir: create usage output

Created usage output for oe-setup-builddir script.

[YOCTO #10751]

(From OE-Core rev: 77606455df7d45fd014c3603e1cf1b24efd37695)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/oe-setup-builddir

@@ -23,6 +23,14 @@ if [ -z "$BUILDDIR" ]; then
     exit 1
 fi
 
+if [ "$1" = '--help' -o "$1" = '-h' ]; then
+    echo 'Usage: oe-setup-builddir'
+    echo ''
+    echo "OpenEmbedded setup-builddir - setup build directory $BUILDDIR"
+    echo ''
+    exit 2
+fi
+
 mkdir -p "$BUILDDIR/conf"
 
 if [ ! -d "$BUILDDIR" ]; then