arm64: dts: marvell: armada-37xx: swap PHYs' order in USB3 controller node

It seems that the Armada 3700 is the only platform where the USB3 specific
PHY is defined before the USB2 specific one in the device tree:

  $ git grep -E 'phy-names[ \t]*=[ \t]*"usb3-phy"[ \t]*,' next-20260327 -- *.dts *.dtsi | tr '\t' ' '
  next-20260327:arch/arm64/boot/dts/marvell/armada-37xx.dtsi:    phy-names = "usb3-phy", "usb2-utmi-otg-phy";

In contrary to this, there are 93 other platforms/boards where 'usb2-phy'
is defined first:

  $ git grep -E 'phy-names[ \t]*=[ \t]*"usb2-phy"[ \t]*,' next-20260327 -- *.dts *.dtsi | wc -l
  93

Swap the order of the USB3 and USB2 PHYs to follow the common pattern
used on other platforms.

No functional changes intended.

Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>