dt-bindings: clock: mediatek: document clk bindings for mediatek mt7986 SoC

This patch adds the binding documentation for topckgen, apmixedsys,
infracfg, and ethernet subsystem clocks.

Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211217121148.6753-2-sam.shih@mediatek.com
Reviewed-by: Ryder Lee <ryder.lee@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,topckgen.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,topckgen.txt
index 5ce7578..b82422b 100644
--- a/Documentation/devicetree/bindings/arm/mediatek/mediatek,topckgen.txt
+++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,topckgen.txt
@@ -14,6 +14,7 @@
 	- "mediatek,mt7622-topckgen"
 	- "mediatek,mt7623-topckgen", "mediatek,mt2701-topckgen"
 	- "mediatek,mt7629-topckgen"
+	- "mediatek,mt7986-topckgen", "syscon"
 	- "mediatek,mt8135-topckgen"
 	- "mediatek,mt8167-topckgen", "syscon"
 	- "mediatek,mt8173-topckgen"