USB: ipaq: handle 4 endpoint devices

The ipaq driver currently enforces one port on all devices. This
is correct for 2 and 3 endpoint devices, but with 4 endpoint devices
meaningful communication occurs on the second pair.

This patch allows 2 ports for 4 endpoint devices.

Signed-off-by: Mark Ellis <mark@mpellis.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>