ARM: dts: lpc32xx: remove usb bus and elevate all children nodes

ARM: dts: lpc32xx: remove usb bus and elevate all children nodes

Remove usb bus and elevate all children nodes because usb bus is not
existed and only group usb devices logically.

Update register address and related full node name.

Fix below CHECK_DTBS warnings:
arm/boot/dts/nxp/lpc/lpc3250-ea3250.dtb: usb (simple-bus): $nodename:0: 'usb' does not match '^([a-z][a-z0-9\\-]+-bus|bus|localbus|soc|axi|ahb|apb)(@.+)?$'
        from schema $id: http://devicetree.org/schemas/simple-bus.yaml#

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>