staging: wilc1000: delete definition USE_WIRELESS

The preprocessor definition, USE_WIRELESS is always in use.
So, this patch deletes the definitions from the makefile and source codes.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>