sata_nv: disable hardreset for generic

of them being unifying probing, hotplug and EH reset paths uniform.
Previously, broken hardreset could go unnoticed as it wasn't used
during probing but when something goes wrong or after hotplug the
problem will surface and bite hard.

OSDL bug 11195 reports that sata_nv generic flavor falls into this
category.  Hardreset itself succeeds but PHY stays offline after
hardreset.  I tried longer debounce timing but the result was the
same.

  http://bugzilla.kernel.org/show_bug.cgi?id=11195

So, it seems we'll have to drop hardreset from the generic flavor.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>