greybus: audio: Cleanup GB protocol connections in case of abrupt codec removal

We need to clean up GB protocl connections, otherwise successive
codec insertions fails repeatedly.

NOTE: As per suggestion, since codec is already removed, one should
not trigger any GB command. It'll cause a delay of atleast TIMEOUT
value.
HOwever, failing to cleanup GB protocol, causes successive module
insertion to fail

Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>