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

Avoid handling of inactive time related wid command in deferred manner.
Instead of posting the wid to workqueue now handle directly from the
caller context.

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