wifi: wilc1000: cancel the connect operation during interface down

Cancel the ongoing connection request to avoid any issue if the
interface is set down before the connection request is completed.
host_int_handle_disconnect was already available, so renamed it and used
the same API for 'ndio_close' cb.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220720160302.231516-6-ajay.kathat@microchip.com