libsndfile: add hash file

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

package/libsndfile/libsndfile.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	59016dbd326abe7e2366ded5c344c853829bebfd1702ef26a07ef662d6aa4882	libsndfile-1.0.25.tar.gz