ASoC: cs53l30: Fix non static symbol warnings

Fixes the following sparse warnings:

sound/soc/codecs/cs53l30.c:182:20: warning:
 symbol 'input1_sel_values' was not declared. Should it be static?
sound/soc/codecs/cs53l30.c:202:20: warning:
 symbol 'input2_sel_values' was not declared. Should it be static?
sound/soc/codecs/cs53l30.c:734:20: warning:
 symbol 'cs53l30_src_rates' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Paul Handrigan <Paul.Handrigan@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>