ASoC: Intel: kbl_rt5663_max98927: rename shadowed variable

ASoC: Intel: kbl_rt5663_max98927: rename shadowed variable

Fix cppcheck warning:

[sound/soc/intel/boards/kbl_rt5663_max98927.c:358] ->
[sound/soc/intel/boards/kbl_rt5663_max98927.c:401]: (style) Local
variable 'channels' shadows outer variable

[sound/soc/intel/boards/kbl_rt5663_max98927.c:358] ->
[sound/soc/intel/boards/kbl_rt5663_max98927.c:457]: (style) Local
variable 'channels' shadows outer variable

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200113210428.27457-11-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>