staging: wilc1000: refactor wilc_set_operation_mode() to avoid deferred handling

Avoid handling of WID_CURRENT_CHANNEL wid command in deferred approach.
Instead of posting the wid to work queue now handle directly from the
caller context. Use structure to fill in the firmware specific format.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>