dt-bindings: i2c: realtek,rtl9301-i2c: extend for clocks and RTL9607C support

Add the "realtek,rtl9607-i2c" compatible for i2c controller on the
RTL9607C SoC series.

Add a clocks property to the properties to describe the i2c reference
clock and make it available for all the compatibles. This i2c reference
clock is assumed to be coming from switchcore region via Lexra bus as
the other SoC peripherals.

According to the info available about the existing devices, they also
have the i2c master controller clocks.

RTL9607C requires the "realtek,scl" and "clocks" to be specified
and so handle it under separate if check for "realtek,rtl9607-i2c".

Signed-off-by: Rustam Adilov <adilov@disroot.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260401180648.337834-6-adilov@disroot.org

Author: Rustam Adilov

Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml

@@ -15,6 +15,8 @@ description:
   assigned to either I2C controller.
   RTL9310 SoCs have equal capabilities but support 12 common SDA lines which
   can be assigned to either I2C controller.
+  RTL9607C SoCs have equal capabilities but each controller only supports 1
+  SCL/SDA line.
 
 properties:
   compatible:
@@ -34,6 +36,7 @@ properties:
       - enum:
           - realtek,rtl9301-i2c
           - realtek,rtl9310-i2c
+          - realtek,rtl9607-i2c
 
   reg:
     items:
@@ -51,6 +54,9 @@ properties:
       The SCL line number of this I2C controller.
     enum: [ 0, 1 ]
 
+  clocks:
+    maxItems: 1
+
 patternProperties:
   '^i2c@[0-9ab]$':
     $ref: /schemas/i2c/i2c-controller.yaml
@@ -81,6 +87,15 @@ allOf:
     then:
       patternProperties:
         '^i2c@[89ab]$': false
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: realtek,rtl9607-i2c
+    then:
+      required:
+        - realtek,scl
+        - clocks
 
 required:
   - compatible