ASoC: lpass-ipq806x: Staticise local symbols

ipq806x_data is not used outside this file, so it can be static.
Fixes the following sparse warning:

	sound/soc/qcom/lpass-ipq806x.c:76:22: warning: symbol 'ipq806x_data'
		was not declared. Should it be static?

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>