dt-bindings: spmi: spmi-mtk-pmif: Document mediatek,mt8195-spmi as fallback of mediatek,mt8186-spmi

The mt8186-spmi is used as compatible with mt8195-spmi on the MT8186,
document this situation.

Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20230324021258.15863-3-allen-kh.cheng@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Author: kuanhsuncheng

Documentation/devicetree/bindings/spmi/mtk,spmi-mtk-pmif.yaml

@@ -18,9 +18,14 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - mediatek,mt6873-spmi
-      - mediatek,mt8195-spmi
+    oneOf:
+      - enum:
+          - mediatek,mt6873-spmi
+          - mediatek,mt8195-spmi
+      - items:
+          - enum:
+              - mediatek,mt8186-spmi
+          - const: mediatek,mt8195-spmi
 
   reg:
     maxItems: 2