mac80211: add missing config override

SVN-Revision: 17331

package/mac80211/Makefile

@@ -472,6 +472,7 @@ MAKE_OPTS:= \
 	CONFIG_LIBERTAS= \
 	CONFIG_LIBERTAS_CS= \
 	CONFIG_LIBERTAS_SDIO= \
+	CONFIG_LIBERTAS_THINFIRM= \
 	CONFIG_IPW2100= \
 	CONFIG_IPW2200= \
 	CONFIG_NL80211=y \