zynqmp: usb: Add usb dwc3 driver support for zynqmp

Added usb dwc3 driver support for zynqmp
this also supports the DFU and LTHOR to download
the linux images on to RAM and cen be booted from
those linux images.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>