[MTD] replace MTD_ROM with MTD_GENERIC_TYPE

No mtd user should ever check for the device type.  Instead, device features
should be checked by the flags - if at all.
As a first step towards type removal, change MTD_ROM into MTD_GENERIC_TYPE.

Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
diff --git a/drivers/mtd/chips/map_rom.c b/drivers/mtd/chips/map_rom.c
index 624c12c..d59ac01 100644
--- a/drivers/mtd/chips/map_rom.c
+++ b/drivers/mtd/chips/map_rom.c
@@ -40,15 +40,13 @@
 	map->fldrv = &maprom_chipdrv;
 	mtd->priv = map;
 	mtd->name = map->name;
-	mtd->type = MTD_ROM;
+	mtd->type = MTD_GENERIC_TYPE;
 	mtd->size = map->size;
 	mtd->read = maprom_read;
 	mtd->write = maprom_write;
 	mtd->sync = maprom_nop;
 	mtd->flags = MTD_CAP_ROM;
-	mtd->erasesize = 131072;
- 	while(mtd->size & (mtd->erasesize - 1))
-		mtd->erasesize >>= 1;
+	mtd->erasesize = map->size;
 
 	__module_get(THIS_MODULE);
 	return mtd;