squashfs: add license information

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/squashfs/squashfs.mk

@@ -7,6 +7,8 @@
 SQUASHFS_VERSION = 4.3
 SQUASHFS_SOURCE = squashfs$(SQUASHFS_VERSION).tar.gz
 SQUASHFS_SITE = http://downloads.sourceforge.net/project/squashfs/squashfs/squashfs$(SQUASHFS_VERSION)
+SQUASHFS_LICENSE = GPLv2+
+SQUASHFS_LICENSE_FILES = COPYING
 
 # no libattr in BR
 SQUASHFS_MAKE_ARGS = XATTR_SUPPORT=0