[PATCH 1/2] arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes

[bryan@bryanhinton.com]

Add stable labels (uart0, uart1, uart2) to the MT7981B SoC UART nodes so
board DTS files can reference them directly. This change is purely
cosmetic and introduces no functional differences.

Verification: Built dtbs and boot-tested mainline Image+DTB via U-Boot on
MT7981B hardware; decompiled DT shows the uart0 label present and the
serial0 alias (or absolute path) resolves to serial@11002000.

Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>
---
 arch/arm64/boot/dts/mediatek/mt7981b.dtsi | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
index 5cbea9cd411f..4ee7fb83000d 100644
--- a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
@@ -94,7 +94,7 @@ pwm@10048000 {
 			#pwm-cells = <2>;
 		};
 
-		serial@11002000 {
+		uart0: serial@11002000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11002000 0 0x100>;
 			interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>;
@@ -105,7 +105,7 @@ serial@11002000 {
 			status = "disabled";
 		};
 
-		serial@11003000 {
+		uart1: serial@11003000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11003000 0 0x100>;
 			interrupts = <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>;
@@ -116,7 +116,7 @@ serial@11003000 {
 			status = "disabled";
 		};
 
-		serial@11004000 {
+		uart2: serial@11004000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11004000 0 0x100>;
 			interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
-- 
2.51.0