libmad: add hash for license file

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libmad/libmad.hash

@@ -1,3 +1,4 @@
 # Locally computed:
 sha256  bbfac3ed6bfbc2823d3775ebb931087371e142bb0e9bb1bee51a76a6e0078690  libmad-0.15.1b.tar.gz
 sha256  0e21f2c6b19337d0b237dacc04f7b90a56be7f359f4c9a2ee0b202d9af0cfa69  frame_length.diff
+sha256  32b1062f7da84967e7019d01ab805935caa7ab7321a7ced0e30ebe75e5df1670  COPYING