arm64: dts: marvell: armada-37xx: Move PCIe max-link-speed property

Move the max-link-speed property of the PCIe node from board specific
device tree files to the generic armada-37xx.dtsi.

Armada 37xx supports only PCIe gen2 speed so max-link-speed property
should be in the generic armada-37xx.dtsi file.
Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts

@@ -132,7 +132,6 @@ &pcie0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pcie_reset_pins &pcie_clkreq_pins>;
 	status = "okay";
-	max-link-speed = <2>;
 	reset-gpios = <&gpiosb 3 GPIO_ACTIVE_LOW>;
 
 	/* enabled by U-Boot if PCIe module is present */

arch/arm64/boot/dts/marvell/armada-37xx.dtsi

@@ -493,6 +493,7 @@ pcie0: pcie@d0070000 {
 					<0 0 0 2 &pcie_intc 1>,
 					<0 0 0 3 &pcie_intc 2>,
 					<0 0 0 4 &pcie_intc 3>;
+			max-link-speed = <2>;
 			phys = <&comphy1 0>;
 			pcie_intc: interrupt-controller {
 				interrupt-controller;