dt-bindings: can: nxp,sja1000: Document RZ/N1 power-domains support

Document RZ/N1 power-domains support. Also update the example with
power-domains property.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/all/20220830164518.1381632-2-biju.das.jz@bp.renesas.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Documentation/devicetree/bindings/net/can/nxp,sja1000.yaml

@@ -30,6 +30,9 @@ properties:
   clocks:
     maxItems: 1
 
+  power-domains:
+    maxItems: 1
+
   reg-io-width:
     $ref: /schemas/types.yaml#/definitions/uint32
     description: I/O register width (in bytes) implemented by this device
@@ -105,6 +108,7 @@ allOf:
     then:
       required:
         - clocks
+        - power-domains
 
 unevaluatedProperties: false
 
@@ -129,4 +133,5 @@ examples:
         reg-io-width = <4>;
         interrupts = <GIC_SPI 95 IRQ_TYPE_LEVEL_HIGH>;
         clocks = <&sysctrl R9A06G032_HCLK_CAN0>;
+        power-domains = <&sysctrl>;
     };