staging: wilc1000: remove ununsed function

The function WILC_WFI_InitPriv() is not used anywhere in the
driver.Hence remove it.

Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>