USB: serial-generic: use a single set of device IDs

The usb-serial-generic driver uses different device IDs for its USB
matching and its serial matching.  This can lead to problems: The
driver can end up getting bound to a USB interface without being
allowed to bind to the corresponding serial port.

This patch (as1557) fixes the problem by using the same device ID
table (the one that can be altered by the "vendor=" and "product="
module parameters) for both purposes.  The unused table is removed.
Now the driver will bind only to the intended devices.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>