acx-mac80211: drop PKG_BUILD_DEPENDS

We already have a DEPENDS on mac80211, which should be enough to ensure
headers are available before build.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

package/kernel/acx-mac80211/Makefile

@@ -16,7 +16,6 @@ PKG_SOURCE_PROTO:=git
 PKG_SOURCE_DATE:=2014-02-16
 PKG_SOURCE_VERSION:=b6fc31491020cb01d2cd1acc170cfa03ced7e726
 PKG_MIRROR_HASH:=58590245715f0e5fb4b57aab6d91071dfb6a97d3273f5aee0b97b1edee030ed0
-PKG_BUILD_DEPENDS:=mac80211
 
 PKG_CONFIG_DEPENDS:= \
 	CONFIG_PACKAGE_MAC80211_DEBUGFS \