libata-core: unblacklist HITACHI drives

The HITACHI HDS7250SASUN500G and HITACHI HDS7225SBSUN250 drives
do not need to be blacklisted, the NCQ problem has been resolved
with the "sata_nv: fix for completion handling" patch.

Signed-off-by David Milburn <dmilburn@redhat.com>

Signed-off-by: Jeff Garzik <jeff@garzik.org>