usb: dwc3: xilinx: Add gpio-reset support

This patch adds a USB GPIO based reset for dwc3-xilinx driver. The PHY
needs to be reset after the completion of phy initialization. As part
of the reset, check for gpio-reset binding before toggling the pin.
This feature is advantageous when the user toggle GPIO to trigger the
ULPI-PHY reset.

Delay of milliseconds is added in between low and high to meet the setup
and hold time requirement of the reset. The reset-gpio error handling is
added for error notification.

Some GPIO controllers must be accessed using message-based buses, like
I2C or SPI, to address this problem, updates GPIO access with sleep API.

This reset is specific to the zynqMp.

Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com>
Link: https://lore.kernel.org/r/20220504075309.6244-3-piyush.mehta@xilinx.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>