slimbus: ngd: add stream support

This patch adds support to stream support, this involve implementing
user specific implementation of Data channel management and channel
management SLIMbus messages.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>