package/gmp: add hashes for license files

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

package/gmp/gmp.hash

@@ -1,2 +1,6 @@
 # Locally calculated after checking pgp signature
 sha256	87b565e89a9a684fe4ebeeddb8399dce2599f9c9049854ca8c0dfbdea0e21912	gmp-6.1.2.tar.xz
+
+# Locally calculated
+sha256	a853c2ffec17057872340eee242ae4d96cbf2b520ae27d903e1b2fef1a5f9d1c	COPYING.LESSERv3
+sha256	8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643	COPYINGv2