nettle: add license info

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/nettle/nettle.mk

@@ -2,6 +2,8 @@ NETTLE_VERSION = 2.5
 NETTLE_SITE = http://www.lysator.liu.se/~nisse/archive
 NETTLE_DEPENDENCIES = gmp
 NETTLE_INSTALL_STAGING = YES
+NETTLE_LICENSE = LGPLv2.1+
+NETTLE_LICENSE_FILES = COPYING.LIB
 
 define NETTLE_DITCH_DEBUGGING_CFLAGS
 	$(SED) '/CFLAGS/ s/ -ggdb3//' $(@D)/configure