usb: dwc3: qcom: Add shutdown handler

usb: dwc3: qcom: Add shutdown handler

Currently during system reboot, SMMU disables its translations
while devices like USB may still be actively using DMA buffers.
This can lead to NOC errors and system crashes due to invalid
memory access.

Address this by adding a shutdown callback to dwc3-qcom, which
ensures proper teardown of UDC stack and prevents DWC3 controller
from accessing memory after SMMU translation is disabled. Reuse
the existing remove callback for this purpose.

Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250725062158.2418961-1-prashanth.k@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>