mac80211: add missing license information

The lincense information for the packages mac80211 are missing.
This commit adds the missing information.

Signed-off-by: Florian Eckert <[email protected]>

package/kernel/mac80211/Makefile

@@ -12,6 +12,9 @@ PKG_NAME:=mac80211
 
 PKG_VERSION:=6.6.15
 PKG_RELEASE:=1
+PKG_LICENSE:=GPL-2.0-only
+PKG_LICENSE_FILES:=COPYING
+
 PKG_SOURCE_URL:=http://mirror2.openwrt.org/sources/
 PKG_HASH:=3bbc461121134fda9089c084a5eed577d05e7837a157edf9a3797937172a3ece