package/libtool: add hash for license files

Signed-off-by: Adam Duskett <Aduskett@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libtool/libtool.hash

@@ -2,3 +2,4 @@
 sha256	7c87a8c2c8c0fc9cd5019e402bed4292462d00a718a7cd5f11218153bf28b26f	libtool-2.4.6.tar.xz
 # License files, locally calculated
 sha256	8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643	COPYING
+sha256	dc626520dcd53a22f727af3ee42c770e56c97a64fe3adb063799d8ab032fe551	libltdl/COPYING.LIB