greybus: some more renames

This patch renames of symbols, for better clarity and consistency.

    cport -> cport_id (when it represents a cport *number*)
    send_svc_msg -> submit_svc (like submit_gbuf)
    greybus_cport_in_data -> greybus_cport_in
    gb_new_ap_msg -> greybus_svc_in (like greybus_cport_in)
    cport->number -> cport->id (like cport_id)

Making the svc and cport message stuff more similar is done with an
eye toward having SVC messages and messages exchanged with other
modules use some more common communication mechanisms.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>