xhci: Remove unused function declarations

xhci: Remove unused function declarations

Commit 674f8438c121 ("xhci: split handling halted endpoints into two
steps") removed xhci_cleanup_stalled_ring() but left declaration.

Commit 25355e046d29 ("xhci: use generic command timer for stop endpoint
commands.") left behind xhci_stop_endpoint_command_watchdog().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240905143300.1959279-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>