mwifiex: don't select lib80211

The driver doesn't use any lib80211 symbols
so it shouldn't select it in Kconfig.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/Kconfig

 config MWIFIEX
 	tristate "Marvell WiFi-Ex Driver"
 	depends on CFG80211
-	select LIB80211
 	---help---
 	  This adds support for wireless adapters based on Marvell
 	  802.11n chipsets.