wl12xx build fails with many undefined symbol errors when MAC80211
and CFG80211 are not enabled, so make WLCORE and WL12XX depend
on MAC80211 (which already depends on CFG80211).

Here are a few of the many build errors:

drivers/built-in.o: In function `wl1271_register_hw':
main.c:(.text+0x4197cd): undefined reference to `ieee80211_register_hw'
drivers/built-in.o: In function `wl1271_rx_streaming_timer':
main.c:(.text+0x419818): undefined reference to `ieee80211_queue_work'
drivers/built-in.o: In function `wl1271_flush_deferred_work':
main.c:(.text+0x419910): undefined reference to `ieee80211_rx'
main.c:(.text+0x419938): undefined reference to `ieee80211_tx_status'
drivers/built-in.o: In function `wl12xx_op_channel_switch':
main.c:(.text+0x419afc): undefined reference to `ieee80211_chswitch_done'
drivers/built-in.o: In function `wl1271_ssid_set':
drivers/built-in.o: In function `wl1271_event_process':
event.c:(.text+0x41fec4): undefined reference to `ieee80211_sched_scan_stopped'
event.c:(.text+0x41ff88): undefined reference to `ieee80211_cqm_rssi_notify'
event.c:(.text+0x42000d): undefined reference to `ieee80211_stop_rx_ba_session'
event.c:(.text+0x420048): undefined reference to `ieee80211_stop_rx_ba_session'
event.c:(.text+0x4200b8): undefined reference to `ieee80211_chswitch_done'
event.c:(.text+0x4201ae): undefined reference to `ieee80211_find_sta'
event.c:(.text+0x4201ba): undefined reference to `ieee80211_report_low_ack'
event.c:(.text+0x42021b): undefined reference to `ieee80211_connection_loss'
drivers/built-in.o: In function `wl1271_tx_complete_packet':
tx.c:(.text+0x4206a6): undefined reference to `ieee80211_get_hdrlen_from_skb'
drivers/built-in.o: In function `wl1271_tx_fill_hdr':
tx.c:(.text+0x4208ca): undefined reference to `ieee80211_hdrlen'
drivers/built-in.o: In function `wl1271_handle_tx_low_watermark':
(.text+0x420e25): undefined reference to `ieee80211_wake_queue'
drivers/built-in.o: In function `wl12xx_rearm_rx_streaming':
(.text+0x420ed9): undefined reference to `ieee80211_queue_work'
drivers/built-in.o: In function `wl1271_tx_work_locked':
(.text+0x421008): undefined reference to `ieee80211_free_txskb'
drivers/built-in.o: In function `wl1271_rx_status.clone.2':
rx.c:(.text+0x421593): undefined reference to `ieee80211_channel_to_frequency'
drivers/built-in.o: In function `wl1271_ps_filter_frames':
ps.c:(.text+0x421a41): undefined reference to `ieee80211_tx_status'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc:	Luciano Coelho <coelho@ti.com>
Cc:	linux-wireless@vger.kernel.org
Cc:	"John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>