arm64: dts: r8a7796: Use SYSC "always-on" PM Domain

Hook up all devices that are part of the CPG/MSSR Clock Domain to the
SYSC "always-on" PM Domain, for a more consistent device-power-area
description in DT.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a7796.dtsi

@@ -122,7 +122,7 @@ scif2: serial@e6e88000 {
 				 <&cpg CPG_CORE R8A7796_CLK_S3D1>,
 				 <&scif_clk>;
 			clock-names = "fck", "brg_int", "scif_clk";
-			power-domains = <&cpg>;
+			power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
 			status = "disabled";
 		};
 	};