gsl: add hash file

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gsl/gsl.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	73bc2f51b90d2a780e6d266d43e487b3dbd78945dd0b04b14ca5980fe28d2f53	gsl-1.16.tar.gz