dt-bindings: serial: snps-dw-apb-uart: Add Synaptics sl2610 uart

Add the compatible for the UARTs of the Synaptics SL2610, which are
compatible with the Synopsys DesignWare APB UART.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20261014110546.415-1-jszhang@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml

@@ -34,7 +34,16 @@ allOf:
       properties:
         resets:
           minItems: 2
-    else:
+
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              enum:
+                - starfive,jh7110-uart
+                - syna,sl2610-uart
+    then:
       properties:
         resets:
           maxItems: 1
@@ -80,6 +89,7 @@ properties:
               - starfive,jh7100-hsuart
               - starfive,jh7100-uart
               - starfive,jh7110-uart
+              - syna,sl2610-uart
               - ti,tda54-uart
               - ultrarisc,dp1000-uart
           - const: snps,dw-apb-uart