dt-bindings: move various timer bindings to timer/ directory

Bindings are supposed to be organized by device class/function. Move
bindings for various timers to timer/ binding directory.

Cc: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/ux500/boards.txt

@@ -26,7 +26,7 @@ interrupt-controller:
 	see binding for interrupt-controller/arm,gic.txt
 
 timer:
-	see binding for arm/twd.txt
+	see binding for timer/arm,twd.txt
 
 clocks:
 	see binding for clocks/ux500.txt

Documentation/devicetree/bindings/pwm/pwm-omap-dmtimer.txt

@@ -2,7 +2,7 @@
 
 Required properties:
 - compatible: Shall contain "ti,omap-dmtimer-pwm".
-- ti,timers: phandle to PWM capable OMAP timer. See arm/omap/timer.txt for info
+- ti,timers: phandle to PWM capable OMAP timer. See timer/ti,timer.txt for info
   about these timers.
 - #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
   the cells format.