libata: move ata_altstatus() to pio data xfer functions

Move ata_altstatus() out from ata_hsm_move() to the pio data xfer
functions like ata_pio_sectors() and atapi_pio_bytes() where it makes
more sense.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>