scsi: wd33c93: Remove dead code related to the long-gone config WD33C93_PIO

The historical commit 5e018f7e60c9 ("Remove PC9800 support") from 2004 in
linux's history.git removed the config WD33C93_PIO to tweak the scsi
wd33c93 driver for the PC9800.

Some dead code in drivers/scsi/wd33c93.[ch] under an ifdef WD33C93_PIO
continued to remain in the repository until now.

Remove this dead code.

This issue was discovered with ./scripts/checkkconfigsymbols.py.

Link: https://lore.kernel.org/r/20220920112921.25275-1-lukas.bulwahn@gmail.com


Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>