staging: wilc1000: rename firmware related constants to follow better namespace

Rename the firmware related macro by prefix with 'WILC_FW_' prefix for
a better namespace. Also, move them to wilc_wlan_if.h file along with other
FW related macros.

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