dt-bindings: timer: Add compatible for Mediatek MT8192

This commit adds dt-binding documentation of timer for Mediatek MT8192 SoC
Platform.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Seiya Wang <seiya.wang@mediatek.com>
Link: https://lore.kernel.org/r/20200814060454.32200-4-seiya.wang@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/timer/mediatek,mtk-timer.txt

@@ -22,6 +22,7 @@ Required properties:
 
 	For those SoCs that use SYST
 	* "mediatek,mt8183-timer" for MT8183 compatible timers (SYST)
+	* "mediatek,mt8192-timer" for MT8192 compatible timers (SYST)
 	* "mediatek,mt7629-timer" for MT7629 compatible timers (SYST)
 	* "mediatek,mt6765-timer" for MT6765 and all above compatible timers (SYST)