nand.h: Cleanup linux/mtd/rawnand.h usage

We only include <linux/mtd/rawnand.h> in <nand.h> for the forward
declaration of struct nand_chip, so do that directly.  Then, include
<linux/mtd/rawnand.h> where required directly.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/mtd/nand/raw/am335x_spl_bch.c b/drivers/mtd/nand/raw/am335x_spl_bch.c
index b6fc5f2..83590a6 100644
--- a/drivers/mtd/nand/raw/am335x_spl_bch.c
+++ b/drivers/mtd/nand/raw/am335x_spl_bch.c
@@ -14,6 +14,7 @@
 #include <asm/io.h>
 #include <linux/delay.h>
 #include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/rawnand.h>
 
 static int nand_ecc_pos[] = CONFIG_SYS_NAND_ECCPOS;
 static struct mtd_info *mtd;