carl9170: Clarify kconfig text

The previous text was confusing, leading readers to think this
driver was a duplicate, and so didn't need to be enabled.

After the removal of the older staging driver, this is the only
driver in mainline for these devices.

Signed-off-by: Lauri Kasanen <cand@gmx.com>
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/carl9170/Kconfig

@@ -5,12 +5,10 @@ config CARL9170
 	select FW_LOADER
 	select CRC32
 	help
-	  This is another driver for the Atheros "otus" 802.11n USB devices.
+	  This is the mainline driver for the Atheros "otus" 802.11n USB devices.
 
-	  This driver provides more features than the original,
-	  but it needs a special firmware (carl9170-1.fw) to do that.
-
-	  The firmware can be downloaded from our wiki here:
+	  It needs a special firmware (carl9170-1.fw), which can be downloaded
+	  from our wiki here:
 	  <http://wireless.kernel.org/en/users/Drivers/carl9170>
 
 	  If you choose to build a module, it'll be called carl9170.