NAND: move board_nand_init to nand.h

Rather than putting the function prototype for board_nand_init() in the one
place where it gets called, put it into nand.h so that every place that also
defines it gets the prototype.  Otherwise, errors can go silently unnoticed
such as using the wrong return value (void rather than int) when defining
the function.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/include/nand.h b/include/nand.h
index b4f316f..065a42c 100644
--- a/include/nand.h
+++ b/include/nand.h
@@ -31,6 +31,8 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
 
+extern int board_nand_init(struct nand_chip *nand);
+
 typedef struct mtd_info nand_info_t;
 
 extern int nand_curr_device;