ide: remove IDE_HFLAG_NO_AUTOTUNE host flag

* Don't set IDE_HFLAG_NO_AUTOTUNE host flag in sgiioc4 and icside
  host drivers - there is no need for it as they don't implement
  ->set_pio_mode method.

* Remove no longer needed IDE_HFLAG_NO_AUTOTUNE host flag.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>