dt-bindings: mfd: syscon: Add mt7988-topmisc

Add compatible for Mediatek mt7988 topmisc syscon.
This hardware block contains 2 functional blocks

- a powercontroller which is not needed (switched by atf)
- a multiplexer for high-speed Combo-Phy

This compatible is only for the multiplexer part.

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250422132438.15735-6-linux@fw-web.de
Signed-off-by: Lee Jones <lee@kernel.org>

Author: frank-w

Documentation/devicetree/bindings/mfd/syscon.yaml

@@ -84,6 +84,7 @@ select:
           - mediatek,mt2701-pctl-a-syscfg
           - mediatek,mt2712-pctl-a-syscfg
           - mediatek,mt6397-pctl-pmic-syscfg
+          - mediatek,mt7988-topmisc
           - mediatek,mt8135-pctl-a-syscfg
           - mediatek,mt8135-pctl-b-syscfg
           - mediatek,mt8173-pctl-a-syscfg
@@ -187,6 +188,7 @@ properties:
           - mediatek,mt2701-pctl-a-syscfg
           - mediatek,mt2712-pctl-a-syscfg
           - mediatek,mt6397-pctl-pmic-syscfg
+          - mediatek,mt7988-topmisc
           - mediatek,mt8135-pctl-a-syscfg
           - mediatek,mt8135-pctl-b-syscfg
           - mediatek,mt8173-pctl-a-syscfg