[S390] sparse: fix sparse static warnings

Make functions and data static to avoid sparse warnings.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c
index 05fb3f7..c28713d 100644
--- a/drivers/s390/net/lcs.c
+++ b/drivers/s390/net/lcs.c
@@ -1970,7 +1970,7 @@
 
 static DEVICE_ATTR(portno, 0644, lcs_portno_show, lcs_portno_store);
 
-const char *lcs_type[] = {
+static const char *lcs_type[] = {
 	"not a channel",
 	"2216 parallel",
 	"2216 channel",