package/gperf: add hash for license file

Signed-off-by: Adam Duskett <Aduskett@gmail.com>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gperf/gperf.hash

@@ -1,2 +1,5 @@
 # Locally calculated after checking pgp signature
 sha256	767112a204407e62dbc3106647cf839ed544f3cf5d0f0523aaa2508623aad63e	gperf-3.0.4.tar.gz
+
+# Locally calculated
+sha256	8ceb4b9ee5adedde47b31e975c1d90c73ad27b6b165a1dcd80c7c545eb65b903	COPYING