transmission: add license information

[Peter: also mention openssl exception]
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/transmission/transmission.mk

@@ -15,10 +15,11 @@ TRANSMISSION_DEPENDENCIES = \
 	openssl \
 	zlib
 TRANSMISSION_AUTORECONF = YES
-
 TRANSMISSION_CONF_OPT = \
 	--disable-libnotify \
 	--enable-lightweight
+TRANSMISSION_LICENSE = GPLv2 or GPLv3 with OpenSSL exception
+TRANSMISSION_LICENSE_FILES = COPYING
 
 ifeq ($(BR2_PACKAGE_TRANSMISSION_UTP),y)
 	TRANSMISSION_CONF_OPT += --enable-utp