arm64: dts: renesas: r8a774c0: Add dynamic power coefficient

Describe the dynamic power coefficient of A53 CPUs.

Based on work by Gaku Inami <gaku.inami.xw@bp.renesas.com> and others.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Link: https://lore.kernel.org/r/1568364608-46548-2-git-send-email-biju.das@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r8a774c0.dtsi

@@ -77,6 +77,7 @@ a53_0: cpu@0 {
 			power-domains = <&sysc R8A774C0_PD_CA53_CPU0>;
 			next-level-cache = <&L2_CA53>;
 			enable-method = "psci";
+			dynamic-power-coefficient = <277>;
 			clocks = <&cpg CPG_CORE R8A774C0_CLK_Z2>;
 			operating-points-v2 = <&cluster1_opp>;
 		};