staging: wilc1000: change data type of wid argument in wilc_wlan_cfg_get

This patch changes data type of wid argument in wilc_wlan_cfg_get from
u32 to u16. It is better to change data type of wid because wid has one
of enum WID_T that is data type of u16. And, there is no need to use u16
type casting when calling wilc_wlan_cfg_get_wid function.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>