ASoC: blackfin: Fix missing break

commit afed4dbe3a043dbd833a53b6b4951e155708afd2 upstream.

Fixes: 4b2ffc205cb9 ('ASoC: Blackfin I2S: add 8-bit sample support')
Reported-by: David Binderman
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>