staging: wilc1000: remove unused elements in 'wilc_priv' struct

Cleanup patch to remove unused element from 'wilc_priv' structure.

Below elements are removed in 'wilc_priv' structure:

struct WILC_WFI_packet *ppool;
struct WILC_WFI_packet *rx_queue; /* List of incoming packets */
int rx_int_enabled;
int tx_packetlen;
u8 *tx_packetdata;
struct napi_struct napi;

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