sata_nv: give up hardreset on nf2

Kernel bz#12176 reports that nf2 hardreset simply doesn't work.  Give
up.  Argh...

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Robert Hancock <hancockr@shaw.ca>
Reported-by: Saro <saro_v@hotmail.it>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>