ASoC: rt5677: rt5677_check_hotword() can be static

Fixes: 21c00e5d ("ASoC: rt5677: Enable jack detect while DSP is running")
Signed-off-by: kbuild test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20191114153304.n4pyix7qadu76tx4@4978f4969bb8


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