pata_hpt37x: inherit prereset() method for HPT374

Commit ab81a505 (pata_hpt37x: unify ->pre_reset
methods) neglected to remove the initializer for the prereset() method from
'hpt374_fn1_port_ops' (it's inherited from 'hpt372_port_ops' anyway), as well
as to update the comment in hpt37x_init_one()...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>