mtd, ubi, ubifs: resync with Linux-3.14

resync ubi subsystem with linux:

commit 455c6fdbd219161bd09b1165f11699d6d73de11c
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Mar 30 20:40:15 2014 -0700

    Linux 3.14

A nice side effect of this, is we introduce UBI Fastmap support
to U-Boot.

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Joerg Krause <jkrause@posteo.de>
diff --git a/drivers/mtd/nand/fsl_upm.c b/drivers/mtd/nand/fsl_upm.c
index 3ae0044..65ce98a 100644
--- a/drivers/mtd/nand/fsl_upm.c
+++ b/drivers/mtd/nand/fsl_upm.c
@@ -153,6 +153,7 @@
 		buf[i] = in_8(chip->IO_ADDR_R);
 }
 
+#if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
 static int upm_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
 {
 	int i;
@@ -165,6 +166,7 @@
 
 	return 0;
 }
+#endif
 
 static int nand_dev_ready(struct mtd_info *mtd)
 {
@@ -191,7 +193,9 @@
 	chip->read_byte = upm_nand_read_byte;
 	chip->read_buf = upm_nand_read_buf;
 	chip->write_buf = upm_nand_write_buf;
+#if defined(CONFIG_MTD_NAND_VERIFY_WRITE)
 	chip->verify_buf = upm_nand_verify_buf;
+#endif
 	if (fun->dev_ready)
 		chip->dev_ready = nand_dev_ready;