ASoC: zx296702-i2s: remove unused ‘format’

ASoC: zx296702-i2s: remove unused ‘format’

In zx_i2s_hw_params(), 'format' is initialized and assigned bits based on
params_format, but never used. So remove it.

sound/soc/zte/zx296702-i2s.c: In function ‘zx_i2s_hw_params’:
sound/soc/zte/zx296702-i2s.c:228:21: warning: variable ‘format’ set but not used [-Wunused-but-set-variable]
  unsigned long val, format;

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>