mtd: physmap_of: allow to specify the mtd name for retro compatiblity

linux,mtd-name allow to specify the mtd name for retro capability with
physmap-flash drivers as boot loader pass the mtd partition via the old
device name physmap-flash.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index 6f19aca..d7f19bc 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -170,6 +170,7 @@
 	resource_size_t res_size;
 	struct mtd_part_parser_data ppdata;
 	bool map_indirect;
+	const char *mtd_name;
 
 	match = of_match_device(of_flash_match, &dev->dev);
 	if (!match)
@@ -178,6 +179,8 @@
 
 	reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
 
+	of_property_read_string(dp, "linux,mtd-name", &mtd_name);
+
 	/*
 	 * Get number of "reg" tuples. Scan for MTD devices on area's
 	 * described by each "reg" region. This makes it possible (including
@@ -234,7 +237,7 @@
 			goto err_out;
 		}
 
-		info->list[i].map.name = dev_name(&dev->dev);
+		info->list[i].map.name = mtd_name ?: dev_name(&dev->dev);
 		info->list[i].map.phys = res.start;
 		info->list[i].map.size = res_size;
 		info->list[i].map.bankwidth = be32_to_cpup(width);