logic_pio: Improve macro argument name

Macro argument "bw" is used for building byte, word, and long-based
functions. Use "bwl" instead, to include long.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>