s390: make various functions static, add declarations to header files

Make various functions static, add declarations to header files to
fix a couple of sparse findings.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 96e52bf..f93cc32 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -524,20 +524,20 @@
 	.llseek		= no_llseek,
 };
 
-void fs3270_create_cb(int minor)
+static void fs3270_create_cb(int minor)
 {
 	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
 	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
 		      NULL, "3270/tub%d", minor);
 }
 
-void fs3270_destroy_cb(int minor)
+static void fs3270_destroy_cb(int minor)
 {
 	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
 	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
 }
 
-struct raw3270_notifier fs3270_notifier =
+static struct raw3270_notifier fs3270_notifier =
 {
 	.create = fs3270_create_cb,
 	.destroy = fs3270_destroy_cb,