iwmc3200wifi: fix link error when CFG80211 is not selected

The patch makes iwmc3200wifi select CFG80211 instead of LIB80211.
This fixed module link error reported by Randy Dunlap
<randy.dunlap@oracle.com> when compiling iwmc3200wifi without
cfg80211 selected. WIRELESS_EXT is also selected by iwmc3200wifi.
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wireless/iwmc3200wifi/Kconfig

 config IWM
 	tristate "Intel Wireless Multicomm 3200 WiFi driver"
 	depends on MMC && WLAN_80211 && EXPERIMENTAL
-	select LIB80211
+	select WIRELESS_EXT
+	select CFG80211
 	select FW_LOADER
 	select RFKILL