dt-bindings: pwm: Add MT2712/MT7622 information

Enhance the MediaTek PWM binding with details about the IP found in the
MT2712 and MT7622 SoCs.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Documentation/devicetree/bindings/pwm/pwm-mediatek.txt

@@ -2,6 +2,8 @@ MediaTek PWM controller
 
 Required properties:
  - compatible: should be "mediatek,<name>-pwm":
+   - "mediatek,mt2712-pwm": found on mt2712 SoC.
+   - "mediatek,mt7622-pwm": found on mt7622 SoC.
    - "mediatek,mt7623-pwm": found on mt7623 SoC.
  - reg: physical base address and length of the controller's registers.
  - #pwm-cells: must be 2. See pwm.txt in this directory for a description of
@@ -10,7 +12,9 @@ Required properties:
  - clock-names: must contain the following:
    - "top": the top clock generator
    - "main": clock used by the PWM core
-   - "pwm1-5": the five per PWM clocks
+   - "pwm1-8": the eight per PWM clocks for mt2712
+   - "pwm1-6": the six per PWM clocks for mt7622
+   - "pwm1-5": the five per PWM clocks for mt7623
  - pinctrl-names: Must contain a "default" entry.
  - pinctrl-0: One property must exist for each entry in pinctrl-names.
    See pinctrl/pinctrl-bindings.txt for details of the property values.