meson-mx-socinfo: Make local function meson_mx_socinfo_init() static

Fixes the following sparse warnings:

drivers/soc/amlogic/meson-mx-socinfo.c:107:12: warning:
 symbol 'meson_mx_socinfo_init' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

drivers/soc/amlogic/meson-mx-socinfo.c

@@ -104,7 +104,7 @@ static const struct of_device_id meson_mx_socinfo_analog_top_ids[] = {
 	{ /* sentinel */ }
 };
 
-int __init meson_mx_socinfo_init(void)
+static int __init meson_mx_socinfo_init(void)
 {
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;