ARM: dts: armada-38x: Add generic compatible to UART nodes

Add generic compatible string "ns16550a" to serial port nodes of Armada
38x.

This makes it possible to use earlycon.

Fixes: 0d3d96ab ("ARM: mvebu: add Device Tree description of the Armada 380/385 SoCs")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm/boot/dts/armada-38x.dtsi

@@ -168,7 +168,7 @@ i2c1: i2c@11100 {
 			};
 
 			uart0: serial@12000 {
-				compatible = "marvell,armada-38x-uart";
+				compatible = "marvell,armada-38x-uart", "ns16550a";
 				reg = <0x12000 0x100>;
 				reg-shift = <2>;
 				interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
@@ -178,7 +178,7 @@ uart0: serial@12000 {
 			};
 
 			uart1: serial@12100 {
-				compatible = "marvell,armada-38x-uart";
+				compatible = "marvell,armada-38x-uart", "ns16550a";
 				reg = <0x12100 0x100>;
 				reg-shift = <2>;
 				interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;