dt-bindings: pwm: Add R-Car H3 device tree bindings

Add device tree bindings for the PWM controller found on R-Car H3 SoCs.
The controller is compatible with the one found in earlier generations
of R-Car SoCs.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt

@@ -7,6 +7,7 @@ Required Properties:
  - "renesas,pwm-r8a7790": for R-Car H2
  - "renesas,pwm-r8a7791": for R-Car M2-W
  - "renesas,pwm-r8a7794": for R-Car E2
+ - "renesas,pwm-r8a7795": for R-Car H3
 - reg: base address and length of the registers block for the PWM.
 - #pwm-cells: should be 2. See pwm.txt in this directory for a description of
   the cells format.