arm64: dts: renesas: r8a7796: Point VSPI via FCPVI to IPMMU-VC0

Hook up the FCPVI devices to allow use of VSPI with IPMMU-VC0.

Based on work for the r8a7795 by Magnus Damm.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

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

@@ -1884,6 +1884,7 @@ fcpvi0: fcp@fe9af000 {
 			clocks = <&cpg CPG_MOD 611>;
 			power-domains = <&sysc R8A7796_PD_A3VC>;
 			resets = <&cpg 611>;
+			iommus = <&ipmmu_vc0 19>;
 		};
 
 		vspd0: vsp@fea20000 {