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 <fe@dev.tdt.de>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [backport]
(cherry picked from commit 3128157ec71c7be5c2e26a04b1f4b5080ebf870a)
Link: https://github.com/openwrt/openwrt/pull/15918


Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/kernel/mac80211/Makefile

@@ -12,6 +12,9 @@ PKG_NAME:=mac80211
 
 PKG_VERSION:=6.1.97-1
 PKG_RELEASE:=1
+PKG_LICENSE:=GPL-2.0-only
+PKG_LICENSE_FILES:=COPYING
+
 PKG_SOURCE_URL:=@KERNEL/linux/kernel/projects/backports/stable/v6.1.97/
 PKG_HASH:=8e9ae2d02f373252dd61f5c6a81c88eec67ca773464d9ef3d844752dc6775540