mtd: extend plat_nand for (read|write)_buf

This patch adds (write|read)_buf callbacks to plat_nand.

The NAND on the TS-7800 provisioned by the FPGA allows readw() and
readl() to be used which gives a 2.5x speed up.  To be able to use this
from the plat_nand driver a hook for read_buf (and also write_buf whilst
we are in there) need to be made available.  This patch adds the hook.

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 7efb9be..0e35375 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -584,6 +584,8 @@
  * @select_chip:	platform specific chip select function
  * @cmd_ctrl:		platform specific function for controlling
  *			ALE/CLE/nCE. Also used to write command and address
+ * @write_buf:		platform specific function for write buffer
+ * @read_buf:		platform specific function for read buffer
  * @priv:		private data to transport driver specific settings
  *
  * All fields are optional and depend on the hardware driver requirements
@@ -594,6 +596,10 @@
 	void		(*select_chip)(struct mtd_info *mtd, int chip);
 	void		(*cmd_ctrl)(struct mtd_info *mtd, int dat,
 				    unsigned int ctrl);
+	void		(*write_buf)(struct mtd_info *mtd,
+				    const uint8_t *buf, int len);
+	void		(*read_buf)(struct mtd_info *mtd,
+				    uint8_t *buf, int len);
 	void		*priv;
 };