xhci: turn off port power in shutdown

xhci: turn off port power in shutdown

If ports are not turned off in shutdown then runtime suspended
self-powered USB devices may survive in U3 link state over S5.

During subsequent boot, if firmware sends an IPC command to program
the port in DISCONNECT state, it will time out, causing significant
delay in the boot time.

Turning off roothub port power is also recommended in xhci
specification 4.19.4 "Port Power" in the additional note.

Cc: [email protected]
Signed-off-by: Mathias Nyman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>