ccache: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/ccache/ccache.mk

@@ -7,6 +7,8 @@
 CCACHE_VERSION = 3.1.8
 CCACHE_SITE    = http://samba.org/ftp/ccache
 CCACHE_SOURCE  = ccache-$(CCACHE_VERSION).tar.bz2
+CCACHE_LICENSE = GPLv3+, others
+CCACHE_LICENSE_FILES = LICENSE.txt GPL-3.0.txt
 
 # When ccache is being built for the host, ccache is not yet
 # available, so we have to use the special C compiler without the