arm64: dts: renesas: r8a7796: Add dynamic power coefficient

Describe the dynamic power coefficient of A57 and A53 CPUs.

Based on work by Gaku Inami <gaku.inami.xw@bp.renesas.com> and others.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

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

@@ -160,6 +160,7 @@ a57_0: cpu@0 {
 			power-domains = <&sysc R8A7796_PD_CA57_CPU0>;
 			next-level-cache = <&L2_CA57>;
 			enable-method = "psci";
+			dynamic-power-coefficient = <854>;
 			clocks = <&cpg CPG_CORE R8A7796_CLK_Z>;
 			operating-points-v2 = <&cluster0_opp>;
 			capacity-dmips-mhz = <1024>;
@@ -187,6 +188,7 @@ a53_0: cpu@100 {
 			next-level-cache = <&L2_CA53>;
 			enable-method = "psci";
 			#cooling-cells = <2>;
+			dynamic-power-coefficient = <277>;
 			clocks = <&cpg CPG_CORE R8A7796_CLK_Z2>;
 			operating-points-v2 = <&cluster1_opp>;
 			capacity-dmips-mhz = <535>;