dt-bindings: pwm: mediatek,mt2712: add compatible for MT7987

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>

Author: frank-w

Documentation/devicetree/bindings/pwm/mediatek,mt2712-pwm.yaml

@@ -25,6 +25,7 @@ properties:
           - mediatek,mt7629-pwm
           - mediatek,mt7981-pwm
           - mediatek,mt7986-pwm
+          - mediatek,mt7987-pwm
           - mediatek,mt7988-pwm
           - mediatek,mt8183-pwm
           - mediatek,mt8365-pwm