Do not let the SPORT be reconfigured until there are no more active
streams.  Then we can let the system reprogram the SPORT state.
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>