dt-bindings: mfd: sl28cpld: Add sa67mcu compatible

The Kontron SMARC-sAM67 module features an on-board house keeping uC.
It's designed to be compatible with the older on-board CPLD used on the
SMARC-sAL28 board. To be prepared for any board specific quirks, add a
specific compatible.

Signed-off-by: Michael Walle <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

Documentation/devicetree/bindings/embedded-controller/kontron,sl28cpld.yaml

@@ -16,7 +16,12 @@ description: |
 
 properties:
   compatible:
-    const: kontron,sl28cpld
+    oneOf:
+      - items:
+          - enum:
+              - kontron,sa67mcu
+          - const: kontron,sl28cpld
+      - const: kontron,sl28cpld
 
   reg:
     description: