greybus: es2: Release reserved cports CDSI0 and CDSI1

Unique ids were reserved for CDSI0 and CDSI1 during _probe, however
missed to release those ids during disconnect. This causes a memory leak
of 128 bytes for each iteration of unipro_reset. Fix this.

Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>