We are going to begin using the mtd->dev.of_node field for MTD device
nodes, so let's add helpers for it. Also, we'll be making some
conversions on spi_nor (and nand_chip eventually) too, so get that ready
with their own helpers.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>