mtd: nand: davinci_nand: update write_page function for keystone RBL

After mtd was synced with Linux 3.14
(ff94bc40)
the number of parameters for write_page function of nand_chip was
changed. The additional two var were needed for subpage write.
As keystone has no supbage write they are not needed. So correct
only function definition by upgrading it's parameter list.
That helps to get ritd of compilation warning.
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@ti.com>

drivers/mtd/nand/davinci_nand.c

@@ -363,6 +363,7 @@ static struct nand_ecclayout nand_keystone_rbl_4bit_layout_oobfirst = {
  * @raw: use _raw version of write_page
  */
 static int nand_davinci_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				   uint32_t offset, int data_len,
 				   const uint8_t *buf, int oob_required,
 				   int page, int cached, int raw)
 {