usb: xhci: tegra: Add shutdown callback for Tegra XUSB

If memory accesses by the Tegra XUSB controller are translated through
the SMMU (System MMU), the hardware may continue accessing memory even
after the SMMU translations have been disabled during the shutdown
process and this can in turn cause unpredictable crashes.
Fix this by adding a shutdown implementation that ensures the hardware
is turned off during system reboot or shutdown.

Signed-off-by: Henry Lin <henryl@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20230727074927.2428611-1-haotienh@nvidia.com


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