ARM: dts: qcom: sdx55/sdx65: Fix CPU power-domain-names

"rpmhpd" is not documented nor used anywhere. The power-domain is used
for performance scaling (cpufreq), so "perf" is the correct name to use.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250410-dt-cpu-schema-v2-7-63d7dc9ddd0a@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm/boot/dts/qcom/qcom-sdx55.dtsi

@@ -57,7 +57,7 @@
 			enable-method = "psci";
 			clocks = <&apcs>;
 			power-domains = <&rpmhpd SDX55_CX>;
-			power-domain-names = "rpmhpd";
+			power-domain-names = "perf";
 			operating-points-v2 = <&cpu_opp_table>;
 		};
 	};

arch/arm/boot/dts/qcom/qcom-sdx65.dtsi

@@ -58,7 +58,7 @@
 			enable-method = "psci";
 			clocks = <&apcs>;
 			power-domains = <&rpmhpd SDX65_CX_AO>;
-			power-domain-names = "rpmhpd";
+			power-domain-names = "perf";
 			operating-points-v2 = <&cpu_opp_table>;
 		};
 	};