mtd/m25p80: add support to parse the partitions by OF node

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
[grant.likely@secretlab.ca: wrap hunk with #ifdef CONFIG_OF]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 6f512b5..ea22520 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -924,6 +924,13 @@
 			nr_parts = data->nr_parts;
 		}
 
+#ifdef CONFIG_OF
+		if (nr_parts <= 0 && spi->dev.of_node) {
+			nr_parts = of_mtd_parse_partitions(&spi->dev,
+					spi->dev.of_node, &parts);
+		}
+#endif
+
 		if (nr_parts > 0) {
 			for (i = 0; i < nr_parts; i++) {
 				DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "