[PATCH] sata_nv: kill struct nv_host_desc and nv_host

nv_host_desc and nv_host are used to discern different generations of
nv controllers.  Kill those.  New EH/hotplug implementation will use
standard port_info/ata_port_operations for that.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>