dt-bindings: dma: rz-dmac: Document RZ/G3S SoC

Document the Renesas RZ/G3S DMAC block. This is identical to the one found
on the RZ/G2L SoC.

Signed-off-by: Claudiu Beznea <[e-mail]>
Acked-by: Rob Herring (Arm) <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/dma/renesas,rz-dmac.yaml

···
           - renesas,r9a07g043-dmac # RZ/G2UL and RZ/Five
           - renesas,r9a07g044-dmac # RZ/G2{L,LC}
           - renesas,r9a07g054-dmac # RZ/V2L
+          - renesas,r9a08g045-dmac # RZ/G3S
       - const: renesas,rz-dmac
 
   reg: