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-m-a2197-03-revA.dts b/arch/arm/dts/zynqmp-m-a2197-03-revA.dts
index cd7654a..7372968 100644
--- a/arch/arm/dts/zynqmp-m-a2197-03-revA.dts
+++ b/arch/arm/dts/zynqmp-m-a2197-03-revA.dts
@@ -359,25 +359,25 @@
 				#gpio-cells = <2>;
 				gpio-line-names = "sw4_1", "sw4_2", "sw4_3", "sw4_4",
 						  "", "", "", "";
-				gtr_sel0 {
+				gtr-sel0 {
 					gpio-hog;
 					gpios = <0 0>;
 					input; /* FIXME add meaning */
 					line-name = "sw4_1";
 				};
-				gtr_sel1 {
+				gtr-sel1 {
 					gpio-hog;
 					gpios = <1 0>;
 					input; /* FIXME add meaning */
 					line-name = "sw4_2";
 				};
-				gtr_sel2 {
+				gtr-sel2 {
 					gpio-hog;
 					gpios = <2 0>;
 					input; /* FIXME add meaning */
 					line-name = "sw4_3";
 				};
-				gtr_sel3 {
+				gtr-sel3 {
 					gpio-hog;
 					gpios = <3 0>;
 					input; /* FIXME add meaning */