meson-gx-socinfo: make local function meson_gx_socinfo_init static

Fixes the following sparse warnings:

drivers/soc/amlogic/meson-gx-socinfo.c:100:12: warning:
 symbol 'meson_gx_socinfo_init' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

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

@@ -97,7 +97,7 @@ static const char *socinfo_to_soc_id(u32 socinfo)
 	return "Unknown";
 }
 
-int __init meson_gx_socinfo_init(void)
+static int __init meson_gx_socinfo_init(void)
 {
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;