Add ->pc_{update,io}_buffers methods to ide_drive_t and use
them instead of {update,io}_buffers ide_pc_intr() arguments.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>