block: CFQ is more than a desktop scheduler

Update Kconfig.iosched entry.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/Kconfig.iosched

@@ -27,7 +27,9 @@ config IOSCHED_CFQ
 	---help---
 	  The CFQ I/O scheduler tries to distribute bandwidth equally
 	  among all processes in the system. It should provide a fair
-	  working environment, suitable for desktop systems.
+	  and low latency working environment, suitable for both desktop
+	  and server systems.
+
 	  This is the default I/O scheduler.
 
 choice