R-Car sound can use SSI/SRC/DVC modules, and these are controlled as
rsnd_mod in rsnd driver. These rsnd_mod has each own function as
callback. Basically these callback function has pair like probe/remove,
start/stop, etc. And, these functions are called by order to each stage
like below.
 1. src->probe
 2. ssi->probe
 3. dvc->probe
 4. src->start
 5. ssi->start
 6. dvc->start
 7. src->stop
 8. ssi->stop
 9. dvc->stop
10. src->remove
11. ssi->remove
12. dvc->remove

But, current rsnd driver doesn't care about its status which indicates
which function is called.
For example, if 5) returns error, 6) is not called. In such case,
9) should not be called. This patch care about each modules status.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>