dt-bindings: mfd: as3722: Drop reference to pm_power_off

Devicetree bindings are supposed to be operating system independent and
should thus not describe how a specific functionality is implemented in
Linux.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Documentation/devicetree/bindings/mfd/as3722.txt

@@ -122,8 +122,7 @@ Following are properties of regulator subnode.
 
 Power-off:
 =========
-AS3722 supports the system power off by turning off all its rail. This
-is provided through pm_power_off.
+AS3722 supports the system power off by turning off all its rails.
 The device node should have the following properties to enable this
 functionality
 ams,system-power-controller: Boolean, to enable the power off functionality