package/aubio: add upstream hash link

Paul Brossier, the aubio maintainer, added a sha256 hash for the
Buildroot package. Thanks !

https://github.com/aubio/aubio/issues/77

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/aubio/aubio.hash

@@ -1,2 +1,2 @@
-# Locally computed
+# From https://aubio.org/pub/aubio-0.4.3.tar.bz2.sha256
 sha256 b62cdb073c0c64ae301917fa162969d42cba45e478bdf1e74490bd87e9cceaab  aubio-0.4.3.tar.bz2