cgroup: update cgroup's document path

cgroup's document path is changed to "cgroup-v1".  update it.

Link: http://lkml.kernel.org/r/1470148443-6509-1-git-send-email-iamyooon@gmail.com
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/Kconfig

@@ -952,7 +952,7 @@ menuconfig CGROUPS
 	  controls or device isolation.
 	  See
 		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
-		- Documentation/cgroups/ (features for grouping, isolation
+		- Documentation/cgroup-v1/ (features for grouping, isolation
 					  and resource control)
 
 	  Say N if unsure.
@@ -1009,7 +1009,7 @@ config BLK_CGROUP
 	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 	CONFIG_BLK_DEV_THROTTLING=y.
 
-	See Documentation/cgroups/blkio-controller.txt for more information.
+	See Documentation/cgroup-v1/blkio-controller.txt for more information.
 
 config DEBUG_BLK_CGROUP
 	bool "IO controller debugging"