iwlegacy: make iwl3945 and iwl4965 select IWLWIFI_LEGACY

Otherwise, IWLWIFI_LEGACY has to be selected independently before the
drivers are made available.
Reported-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>

drivers/net/wireless/iwlegacy/Kconfig

 config IWLWIFI_LEGACY
-	tristate "Intel Wireless Wifi legacy devices"
-	depends on PCI && MAC80211
+	tristate
 	select FW_LOADER
 	select NEW_LEDS
 	select LEDS_CLASS
@@ -65,7 +64,8 @@ endmenu
 
 config IWL4965
 	tristate "Intel Wireless WiFi 4965AGN (iwl4965)"
-	depends on IWLWIFI_LEGACY
+	depends on PCI && MAC80211
+	select IWLWIFI_LEGACY
 	---help---
 	  This option enables support for
 
@@ -92,7 +92,8 @@ config IWL4965
 
 config IWL3945
 	tristate "Intel PRO/Wireless 3945ABG/BG Network Connection (iwl3945)"
-	depends on IWLWIFI_LEGACY
+	depends on PCI && MAC80211
+	select IWLWIFI_LEGACY
 	---help---
 	  Select to build the driver supporting the: