usb: Add versal-usb2-ctrl-regs module

usb: Add versal-usb2-ctrl-regs module

This module emulates control registers of versal usb2 controller, this is added
just to make guest happy. In general this module would control the phy-reset
signal from usb controller, data coherency of the transactions, signals
the host system errors received from controller.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Signed-off-by: Vikram Garhwal <fnu.vikram@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1607023357-5096-2-git-send-email-sai.pavan.boddu@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>