usb: plusb: Add support for PL-25A1

This patch adds support for the PL-25A1 by adding the appropriate
USB ID's. This chip is used in the Belkin 'Windows Easy Transfer'
Cables.

Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: David S. Miller <davem@davemloft.net>