ARM: dts: armada-39x: Fix compatible string for gpios

Armada 39x supports per CPU interrupts for gpios, like Armada XP.

So add compatible string "marvell,armadaxp-gpio" for Armada 39x GPIO nodes.

Driver gpio-mvebu.c which handles both pre-XP and XP variants already
provides support for per CPU interrupts on XP and newer variants.
Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: d81a914f ("ARM: dts: mvebu: armada-39x: add missing nodes describing GPIO's")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm/boot/dts/armada-39x.dtsi

@@ -213,7 +213,7 @@ nand_pins: nand-pins {
 			};
 
 			gpio0: gpio@18100 {
-				compatible = "marvell,orion-gpio";
+				compatible = "marvell,armadaxp-gpio", "marvell,orion-gpio";
 				reg = <0x18100 0x40>;
 				ngpios = <32>;
 				gpio-controller;
@@ -227,7 +227,7 @@ gpio0: gpio@18100 {
 			};
 
 			gpio1: gpio@18140 {
-				compatible = "marvell,orion-gpio";
+				compatible = "marvell,armadaxp-gpio", "marvell,orion-gpio";
 				reg = <0x18140 0x40>;
 				ngpios = <28>;
 				gpio-controller;