arm64: zynqmp: Do not use '_' in DT node names

Using '_' is not recommended for node names. Use '-' instead.
Pretty much run seds below for node names.
s/heartbeat_led/heartbeat-led/
s/gtr_sel/gtr-sel/
s/zynqmp_ipi/zynqmp-ipi/
s/nvmem_firmware/nvmem-firmware/
s/soc_revision/soc-revision/

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/dd33d6cb0595ffedab117d477f4a3c9d9eb11715.1695808665.git.michal.simek@amd.com
diff --git a/arch/arm/dts/zynqmp.dtsi b/arch/arm/dts/zynqmp.dtsi
index 30bd7b4..f03c201 100644
--- a/arch/arm/dts/zynqmp.dtsi
+++ b/arch/arm/dts/zynqmp.dtsi
@@ -136,7 +136,7 @@
 		};
 	};
 
-	zynqmp_ipi: zynqmp_ipi {
+	zynqmp_ipi: zynqmp-ipi {
 		bootph-all;
 		compatible = "xlnx,zynqmp-ipi-mailbox";
 		interrupt-parent = <&gic>;
@@ -206,12 +206,12 @@
 				mbox-names = "tx", "rx";
 			};
 
-			nvmem_firmware {
+			nvmem-firmware {
 				compatible = "xlnx,zynqmp-nvmem-fw";
 				#address-cells = <1>;
 				#size-cells = <1>;
 
-				soc_revision: soc_revision@0 {
+				soc_revision: soc-revision@0 {
 					reg = <0x0 0x4>;
 				};
 			};