mtd: nand: raw: convert nand_dt_init() to ofnode_xx() interface

nand_dt_init() is still using fdtdec_xx() interface.
If OF_LIVE flag is enabled, dt property can't be get anymore.
Updating all fdtdec_xx() interface to ofnode_xx() to solve this issue.

For doing this, node parameter type must be ofnode.

First idea was to convert "node" parameter to ofnode type inside
nand_dt_init() using offset_to_ofnode(node). But offset_to_ofnode()
is not bijective, in case OF_LIVE flag is enabled, it performs an assert().

So, this leads to update nand_chip struct flash_node field from int to
ofnode and to update all nand_dt_init() callers.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 7bc6ec7..c378f08 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -1711,7 +1711,7 @@
 	 * in the DT.
 	 */
 	nand->ecc.mode = NAND_ECC_HW;
-	nand->flash_node = node;
+	nand->flash_node = offset_to_ofnode(node);
 	nand->select_chip = sunxi_nfc_select_chip;
 	nand->cmd_ctrl = sunxi_nfc_cmd_ctrl;
 	nand->read_buf = sunxi_nfc_read_buf;