mtd: mchp23k256: add partitioning support

Setting the of_node for the mtd device allows the generic mtd code to
setup the partitions.

[Editorial note (Brian): patch still pending on fixing up the "aligned
to eraseblock" partition sanity check, given that this SRAM has no
eraseblocks.]
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/devices/mchp23k256.c

@@ -143,6 +143,7 @@ static int mchp23k256_probe(struct spi_device *spi)
 
 	data = dev_get_platdata(&spi->dev);
 
+	mtd_set_of_node(&flash->mtd, spi->dev.of_node);
 	flash->mtd.dev.parent	= &spi->dev;
 	flash->mtd.type		= MTD_RAM;
 	flash->mtd.flags	= MTD_CAP_RAM;