ARM: sun8i: Use - instead of @ for DT OPP entries

Compiling the DT file with W=1, DTC warns like follows:

Warning (unit_address_vs_reg): Node /opp_table0/opp@1000000000 has a
unit name, but no reg property

Fix this by replacing '@' with '-' as the OPP nodes will never have a
"reg" property.
Reported-by: Krzysztof Kozlowski <krzk@kernel.org>
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-a33-sinlinx-sina33.dts

@@ -88,13 +88,13 @@ &cpu0 {
 };
 
 &cpu0_opp_table {
-	opp@1104000000 {
+	opp-1104000000 {
 		opp-hz = /bits/ 64 <1104000000>;
 		opp-microvolt = <1320000>;
 		clock-latency-ns = <244144>; /* 8 32k periods */
 	};
 
-	opp@1200000000 {
+	opp-1200000000 {
 		opp-hz = /bits/ 64 <1200000000>;
 		opp-microvolt = <1320000>;
 		clock-latency-ns = <244144>; /* 8 32k periods */

arch/arm/boot/dts/sun8i-a33.dtsi

@@ -50,73 +50,73 @@ cpu0_opp_table: opp_table0 {
 		compatible = "operating-points-v2";
 		opp-shared;
 
-		opp@120000000 {
+		opp-120000000 {
 			opp-hz = /bits/ 64 <120000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@240000000 {
+		opp-240000000 {
 			opp-hz = /bits/ 64 <240000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@312000000 {
+		opp-312000000 {
 			opp-hz = /bits/ 64 <312000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@408000000 {
+		opp-408000000 {
 			opp-hz = /bits/ 64 <408000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@480000000 {
+		opp-480000000 {
 			opp-hz = /bits/ 64 <480000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@504000000 {
+		opp-504000000 {
 			opp-hz = /bits/ 64 <504000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@600000000 {
+		opp-600000000 {
 			opp-hz = /bits/ 64 <600000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@648000000 {
+		opp-648000000 {
 			opp-hz = /bits/ 64 <648000000>;
 			opp-microvolt = <1040000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@720000000 {
+		opp-720000000 {
 			opp-hz = /bits/ 64 <720000000>;
 			opp-microvolt = <1100000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@816000000 {
+		opp-816000000 {
 			opp-hz = /bits/ 64 <816000000>;
 			opp-microvolt = <1100000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@912000000 {
+		opp-912000000 {
 			opp-hz = /bits/ 64 <912000000>;
 			opp-microvolt = <1200000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
 		};
 
-		opp@1008000000 {
+		opp-1008000000 {
 			opp-hz = /bits/ 64 <1008000000>;
 			opp-microvolt = <1200000>;
 			clock-latency-ns = <244144>; /* 8 32k periods */
@@ -164,15 +164,15 @@ iio-hwmon {
 	mali_opp_table: gpu-opp-table {
 		compatible = "operating-points-v2";
 
-		opp@144000000 {
+		opp-144000000 {
 			opp-hz = /bits/ 64 <144000000>;
 		};
 
-		opp@240000000 {
+		opp-240000000 {
 			opp-hz = /bits/ 64 <240000000>;
 		};
 
-		opp@384000000 {
+		opp-384000000 {
 			opp-hz = /bits/ 64 <384000000>;
 		};
 	};