ASoC: codecs: jz4770: Remove defined but never used variable 'mic_boost_tlv'

Fixes the following W=1 kernel build warning(s):

 In file included from include/sound/tlv.h:10,
 from sound/soc/codecs/jz4770.c:19:
 sound/soc/codecs/jz4770.c:306:35: warning: ‘mic_boost_tlv’ defined but not used [-Wunused-const-variable=]
 306 | static const DECLARE_TLV_DB_SCALE(mic_boost_tlv, 0, 400, 0);
 | ^~~~~~~~~~~~~
 include/uapi/sound/tlv.h:64:15: note: in definition of macro ‘SNDRV_CTL_TLVD_DECLARE_DB_SCALE’
 64 | unsigned int name[] = { | ^~~~
 sound/soc/codecs/jz4770.c:306:14: note: in expansion of macro ‘DECLARE_TLV_DB_SCALE’
 306 | static const DECLARE_TLV_DB_SCALE(mic_boost_tlv, 0, 400, 0);
 | ^~~~~~~~~~~~~~~~~~~~

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Cc: ter Huurne <maarten@treewalker.org>
Link: https://lore.kernel.org/r/20200707190612.97799-9-pierre-louis.bossart@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>