staging: wilc1000: remove unnecessary header file inclusion for wilc

Remove the unnecessary file inclusion in the source code. Also follow
the convension to first include the system header then project specific
header files.

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