greybus: hd: Add API to release reserved CPorts

It is required to release all unique ids registered via ida_get_simple
to avoid any possible memory leak. cport_release() already exists with
special handling for ES2_CPORT_CDSI1, i.e. updating in_use flag without
removing associated ida.

So, added another API to release reserved cports CDSI0 and CDSI1. This
is intended to  be used only during es2_destroy().

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>