arm64: dts: renesas: r8a77970: Update IPMMU DS1 bit number

Judging by "R-Car-Gen3-rev0.80" IPMMU IMSSTR register documentation
for [R-Car V3M] the DS1 bit field should be bit 0.

Update the ipmmu-main property to make it match the data sheet.

Fixes: ce3b52a1 ("arm64: dts: renesas: r8a77970: Add IPMMU device nodes")
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77970.dtsi

@@ -160,7 +160,7 @@ ipmmu_rt: mmu@ffc80000 {
 		ipmmu_ds1: mmu@e7740000 {
 			compatible = "renesas,ipmmu-r8a77970";
 			reg = <0 0xe7740000 0 0x1000>;
-			renesas,ipmmu-main = <&ipmmu_mm 1>;
+			renesas,ipmmu-main = <&ipmmu_mm 0>;
 			power-domains = <&sysc R8A77970_PD_ALWAYS_ON>;
 			#iommu-cells = <1>;
 		};