[MTD NAND] Make various initfuncs static, remove #ifdef MODULE from exitfuncs

We all inherited the same error from the original NAND board driver which
got copied and changed. Fix them all at once...

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/cs553x_nand.c b/drivers/mtd/nand/cs553x_nand.c
index d5b0551..bf25125 100644
--- a/drivers/mtd/nand/cs553x_nand.c
+++ b/drivers/mtd/nand/cs553x_nand.c
@@ -267,7 +267,7 @@
 	return err;
 }
 
-int __init cs553x_init(void)
+static int __init cs553x_init(void)
 {
 	int err = -ENXIO;
 	int i;