staging: r8188eu: remove unused macros

Remove LE_BITS_TO_1BYTE and relevant macros because they are not used
anywhere.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Nam Cao <namcaov@gmail.com>
Link: https://lore.kernel.org/r/a7f700c0688a16bb697fb693894f4c16594fd483.1655220367.git.namcaov@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>