ide: Fix drive's DWORD-IO handling

According the documentation, id[ATA_ID_DWORD_IO] is non-zero if
the drive supports dword IO, while the code disables support by
setting IDE_DFLAG_NO_IO_32BIT. In addition, this word has been
reused by the ATA8 specification. This patch fixes both cases.

Signed-off-by: Mario Schwalbe <schwalbe@inf.tu-dresden.de>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[bart: remove id[ATA_ID_DWORD_IO] check altogether per Sergei's suggestion]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>