usb: rename usb_port device objects

The current port name "portX" is ambiguous.  Before adding more port
messages rename ports to "<hub-device-name>-portX"

This is an ABI change, but the suspicion is that it will go unnoticed as
the port power control implementation has been broken since its
introduction.  If however, someone was relying on the old name we can
add sysfs links from the old name to the new name.

Additionally, it unifies/simplifies port dev_printk messages and modifies
instances of:
	dev_XXX(hub->intfdev, ..."port %d"...
	dev_XXX(&hdev->dev, ..."port%d"...
into:
	dev_XXX(&port_dev->dev, ...

Now that the names are unique usb_port devices it would be nice if they
could be included in /sys/bus/usb.  However, it turns out that this
breaks 'lsusb -t'.  For now, create a dummy port driver so that print
messages are prefixed "usb 1-1-port3" rather than the
subsystem-ambiguous " 1-1-port3".

Finally, it corrects an odd usage of sscanf("port%d") in usb-acpi.c.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>