[PATCH] sata_nv: kill not-working hotplug code

sata_nv contained hotplug code which is mainly for demonstrating how
hotplug event is handled.  This patch kills the demo code in
prepration for real hotplug implementation.

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