mtd: physmap_of: Add non-obsolete map_rom probe

Previously, the only way to map a NOR device as a simple ROM was to
use the obsolete "direct-mapped" compatible binding (which further
requires device_type = "nor" and probe-type = "NOR" properties).

This patch adds an "mtd-rom" compatible binding to the "map_rom"
probe type.

Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/maps/physmap_of.c

@@ -339,6 +339,10 @@ static struct of_device_id of_flash_match[] = {
 		.compatible     = "mtd-ram",
 		.data           = (void *)"map_ram",
 	},
+	{
+		.compatible     = "mtd-rom",
+		.data           = (void *)"map_rom",
+	},
 	{
 		.type		= "rom",
 		.compatible	= "direct-mapped"