hikey: remove redundant CONFIG_DRIVER_NL80211 :=y

When having following :

BOARD_WPA_SUPPLICANT_DRIVER := NL80211
BOARD_HOSTAPD_DRIVER := NL80211

CONFIG_DRIVER_NL80211 will be set automatically inside of
wpa_supplicant/Android.mk and hostapd/Android.mk

ifneq ($(BOARD_WPA_SUPPLICANT_DRIVER),)
  CONFIG_DRIVER_$(BOARD_WPA_SUPPLICANT_DRIVER) := y
endif

ifneq ($(BOARD_HOSTAPD_DRIVER),)
  WPA_BUILD_HOSTAPD := true
  CONFIG_DRIVER_$(BOARD_HOSTAPD_DRIVER) := y
endif

So, remove redundant CONFIG_DRIVER_NL80211 :=y.

Notes: didn't tested since no hardware avaiable.

Change-Id: I5c8de5681fadb9126cdd6ca5de6b9615e52bfc21
Signed-off-by: Bin Chen <bin.chen@linaro.org>
diff --git a/BoardConfigCommon.mk b/BoardConfigCommon.mk
index c0b14c5..a9dc47d 100644
--- a/BoardConfigCommon.mk
+++ b/BoardConfigCommon.mk
@@ -26,7 +26,6 @@
 WPA_SUPPLICANT_VERSION := VER_0_8_X
 BOARD_WPA_SUPPLICANT_DRIVER := NL80211
 BOARD_HOSTAPD_DRIVER := NL80211
-CONFIG_DRIVER_NL80211 := y
 
 TARGET_NO_BOOTLOADER := true
 TARGET_NO_KERNEL := false