arm64: zynqmp: Setup clock-output-names for si570 chips

If there are more instances of si570 clock-output-names property
should be used for differentiation of clock output.
The patch is adding this optional properties for all zynqmp boards with
si570 chip.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revA.dts

@@ -389,6 +389,7 @@ si570_1: clock-generator@5d { /* USER SI570 - u42 */
 				temperature-stability = <50>;
 				factory-fout = <300000000>;
 				clock-frequency = <300000000>;
+				clock-output-names = "si570_user";
 			};
 		};
 		i2c@3 {
@@ -402,6 +403,7 @@ si570_2: clock-generator@5d { /* USER MGT SI570 - u56 */
 				temperature-stability = <50>; /* copy from zc702 */
 				factory-fout = <156250000>;
 				clock-frequency = <148500000>;
+				clock-output-names = "si570_mgt";
 			};
 		};
 		i2c@4 {

arch/arm64/boot/dts/xilinx/zynqmp-zcu106-revA.dts

@@ -388,6 +388,7 @@ si570_1: clock-generator@5d { /* USER SI570 - u42 */
 				temperature-stability = <50>;
 				factory-fout = <300000000>;
 				clock-frequency = <300000000>;
+				clock-output-names = "si570_user";
 			};
 		};
 		i2c@3 {
@@ -401,6 +402,7 @@ si570_2: clock-generator@5d { /* USER MGT SI570 - u56 */
 				temperature-stability = <50>; /* copy from zc702 */
 				factory-fout = <156250000>;
 				clock-frequency = <148500000>;
+				clock-output-names = "si570_mgt";
 			};
 		};
 		i2c@4 {

arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts

@@ -304,6 +304,7 @@ si570_1: clock-generator@5d { /* USER SI570 - u47 */
 				temperature-stability = <50>;
 				factory-fout = <300000000>;
 				clock-frequency = <300000000>;
+				clock-output-names = "si570_user";
 			};
 		};
 		i2c@3 {
@@ -317,6 +318,7 @@ si570_2: clock-generator@5d { /* USER MGT SI570 - u49 */
 				temperature-stability = <50>;
 				factory-fout = <156250000>;
 				clock-frequency = <148500000>;
+				clock-output-names = "si570_mgt";
 			};
 		};
 		i2c@4 {