usb: dwc3: Ignore late xferNotReady event to prevent halt timeout

usb: dwc3: Ignore late xferNotReady event to prevent halt timeout

During a device-initiated disconnect, the End Transfer command resets
the event filter, allowing a new xferNotReady event to be generated
before the controller is fully halted. Processing this late event
incorrectly triggers a Start Transfer, which prevents the controller
from halting and results in a DSTS.DEVCTLHLT bit polling timeout.

Ignore the late xferNotReady event if the controller is already in a
disconnected state.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250807090700.2397190-1-khtsai@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>