arm64: dts: marvell: armada-37xx: drop 'marvell,usb-misc-reg' from USB host nodes

arm64: dts: marvell: armada-37xx: drop 'marvell,usb-misc-reg' from USB host nodes

The 'marvell,usb-misc-reg' property is present both in the EHCI and
in the XHCI USB host device nodes, however it is not documented. Thus
'make dtbs_check' produces warnings like these:

  /arch/arm64/boot/dts/marvell/armada-3720-db.dtb: usb@58000 (marvell,armada3700-xhci): Unevaluated properties are not allowed ('marvell,usb-misc-reg' was unexpected)
          from schema $id: http://devicetree.org/schemas/usb/generic-xhci.yaml
  /arch/arm64/boot/dts/marvell/armada-3720-db.dtb: usb@5e000 (marvell,armada-3700-ehci): Unevaluated properties are not allowed ('marvell,usb-misc-reg' was unexpected)
          from schema $id: http://devicetree.org/schemas/usb/generic-ehci.yaml

Apart from the fact that the properties are not documented, those are
not even used by any USB host drivers. Due to this, drop the properties
in order to get rid of the warnings.

Note:

With the same name, there is a property used for the Armada 3700 USB
UTMI PHYs of which dt-bindings documentation has been added in commit
e60958699afa ("dt-bindings: phy: mvebu-utmi: add UTMI PHY bindings").

Additionally, the property is handled by the 'phy-mvebu-a3700-utmi'
driver since commit cc8b7a0ae866 ("phy: add A3700 UTMI PHY driver").

When the nodes of the UTMI PHYs has been added to the SoC dtsi by
commit 05d168a56fae ("arm64: dts: marvell: armada-37xx: declare USB2
UTMI PHYs"), the properties has been added to the USB host controller
nodes also. According to the commit message this was unintentional,
however in regard to the USB hosts, neither the respective documentation,
nor driver support has been added into the tree since that.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>