Add IDE_AFLAG_{SRFP,WP} drive->atapi_flags and use them
instead of ->{srfp,wp} struct ide_floppy_obj fields.

There should be no functional changes caused by this patch.
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>