ASoC: codecs: wcd-common: fix signedness bug in wcd_dt_parse_micbias_info()

ASoC: codecs: wcd-common: fix signedness bug in wcd_dt_parse_micbias_info()

The error handling does not work because common->micb_vout[] is an array
of u32.  We need a signed variable to store negative error codes.

Fixes: 4f16b6351bbf ("ASoC: codecs: wcd: add common helper for wcd codecs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Link: https://patch.msgid.link/aNKEZ3VqJ8js208v@stanley.mountain
Signed-off-by: Mark Brown <broonie@kernel.org>