staging: wilc1000: refactor code to avoid static variables for config parameters

Refactor the code in wilc_wlan_cfg.c file to avoid the use of static
variables. Move the static variables as part of wilc struct and also
dynamically allocating memory for keeping those variables.

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