dt-bindings: display: sun6i-dsi: Fix clock conditional

The A64 case should have limited maxItems, instead of duplicating the
minItems value from the main binding. While here, simplify the binding
by making this an "else" case of the two-clock conditional block.

Fixes: fe5040f284 ("dt-bindings: sun6i-dsi: Document A64 MIPI-DSI controller")
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221107053552.2330-2-samuel@sholland.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Documentation/devicetree/bindings/display/allwinner,sun6i-a31-mipi-dsi.yaml

@@ -78,16 +78,10 @@ allOf:
       required:
         - clock-names
 
-  - if:
-      properties:
-        compatible:
-          contains:
-            const: allwinner,sun50i-a64-mipi-dsi
-
-    then:
+    else:
       properties:
         clocks:
-          minItems: 1
+          maxItems: 1
 
 unevaluatedProperties: false