staging: wilc1000: fixes prefer using the BIT macro

This patch fixes the warning reported by checkpatch.pl
for prefer using the BIT macro.
And, removes unnecessary bit increase defines.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>