rfkill: Move "state" sysfs file back to stable

There is still quite a bit of code using this interface, so we can't
just remove it. Hopefully it will be possible in the future, but since
its scheduled removal date is past 2 years already, we are better having
the documentation reflecting the current state of things.

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: jprvita

Documentation/ABI/obsolete/sysfs-class-rfkill

@@ -5,9 +5,6 @@ For details to this subsystem look at Documentation/rfkill.txt.
 For the deprecated /sys/class/rfkill/*/claim knobs of this interface look in
 Documentation/ABI/removed/sysfs-class-rfkill.
 
-For the deprecated /sys/class/rfkill/*/state knobs of this interface look in
-Documentation/ABI/obsolete/sysfs-class-rfkill.
-
 What: 		/sys/class/rfkill
 Date:		09-Jul-2007
 KernelVersion:	v2.6.22
@@ -44,6 +41,28 @@ Values: 	A numeric value.
 		1: true
 
 
+What:		/sys/class/rfkill/rfkill[0-9]+/state
+Date:		09-Jul-2007
+KernelVersion	v2.6.22
+Contact:	linux-wireless@vger.kernel.org
+Description: 	Current state of the transmitter.
+		This file was scheduled to be removed in 2014, but due to its
+		large number of users it will be sticking around for a bit
+		longer. Despite it being marked as stabe, the newer "hard" and
+		"soft" interfaces should be preffered, since it is not possible
+		to express the 'soft and hard block' state of the rfkill driver
+		through this interface. There will likely be another attempt to
+		remove it in the future.
+Values: 	A numeric value.
+		0: RFKILL_STATE_SOFT_BLOCKED
+			transmitter is turned off by software
+		1: RFKILL_STATE_UNBLOCKED
+			transmitter is (potentially) active
+		2: RFKILL_STATE_HARD_BLOCKED
+			transmitter is forced off by something outside of
+			the driver's control.
+
+
 What:		/sys/class/rfkill/rfkill[0-9]+/hard
 Date:		12-March-2010
 KernelVersion	v2.6.34