pwm: Update DT bindings to reference pwm.txt for cells documentation

The PWM client cells format is documented in the generic pwm.txt
documentation and duplicated in all PWM driver bindings. Remove
duplicate information and reference pwm.txt instead.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
index ac67c68..4caa1a7 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
@@ -19,13 +19,9 @@
 - reg: base address and size of register area
 - interrupts: list of timer interrupts (one interrupt per timer, starting at
   timer 0)
-- #pwm-cells: number of cells used for PWM specifier - must be 3
-   the specifier format is as follows:
-     - phandle to PWM controller node
-     - index of PWM channel (from 0 to 4)
-     - PWM signal period in nanoseconds
-     - bitmask of optional PWM flags:
-        0x1 - invert PWM signal
+- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+  the cells format. The only third cell flag supported by this binding is
+  PWM_POLARITY_INVERTED.
 
 Optional properties:
 - samsung,pwm-outputs: list of PWM channels used as PWM outputs on particular