dt-bindings: Remove alt_ref from versal

The alt_ref is present only in Versal-net devices.
Other versal devices do not have it. So remove alt_ref
for versal.

Fixes: 352546805a ("dt-bindings: clock: Add bindings for versal clock driver")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@amd.com>

Link: https://lore.kernel.org/r/20231128104348.16372-1-shubhrajyoti.datta@amd.com
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/xlnx,versal-clk.yaml

@@ -31,11 +31,11 @@ properties:
   clocks:
     description: List of clock specifiers which are external input
       clocks to the given clock controller.
-    minItems: 3
+    minItems: 2
     maxItems: 8
 
   clock-names:
-    minItems: 3
+    minItems: 2
     maxItems: 8
 
 required:
@@ -59,15 +59,34 @@ allOf:
         clocks:
           items:
             - description: reference clock
-            - description: alternate reference clock
             - description: alternate reference clock for programmable logic
 
         clock-names:
           items:
             - const: ref
-            - const: alt_ref
             - const: pl_alt_ref
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - xlnx,versal-net-clk
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: reference clock
+            - description: alternate reference clock for programmable logic
+            - description: alternate reference clock
+
+        clock-names:
+          items:
+            - const: ref
+            - const: pl_alt_ref
+            - const: alt_ref
+
   - if:
       properties:
         compatible:
@@ -110,8 +129,8 @@ examples:
         versal_clk: clock-controller {
           #clock-cells = <1>;
           compatible = "xlnx,versal-clk";
-          clocks = <&ref>, <&alt_ref>, <&pl_alt_ref>;
-          clock-names = "ref", "alt_ref", "pl_alt_ref";
+          clocks = <&ref>,  <&pl_alt_ref>;
+          clock-names = "ref", "pl_alt_ref";
         };
       };
     };

Documentation/devicetree/bindings/firmware/xilinx/xlnx,zynqmp-firmware.yaml

@@ -95,8 +95,8 @@ examples:
       versal_clk: clock-controller {
         #clock-cells = <1>;
         compatible = "xlnx,versal-clk";
-        clocks = <&ref>, <&alt_ref>, <&pl_alt_ref>;
-        clock-names = "ref", "alt_ref", "pl_alt_ref";
+        clocks = <&ref>, <&pl_alt_ref>;
+        clock-names = "ref", "pl_alt_ref";
       };
     };