mtd: convert remaining users to mtd_device_register()

The older add_mtd_device()/add_mtd_partitions() and their removal
counterparts will soon be gone.  Replace uses with mtd_device_register()
and mtd_device_unregister().

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/devices/doc2001plus.c b/drivers/mtd/devices/doc2001plus.c
index 8b36fa7..09ae0ad 100644
--- a/drivers/mtd/devices/doc2001plus.c
+++ b/drivers/mtd/devices/doc2001plus.c
@@ -499,7 +499,7 @@
 		docmilpluslist = mtd;
 		mtd->size  = this->totlen;
 		mtd->erasesize = this->erasesize;
-		add_mtd_device(mtd);
+		mtd_device_register(mtd, NULL, 0);
 		return;
 	}
 }
@@ -1091,7 +1091,7 @@
 		this = mtd->priv;
 		docmilpluslist = this->nextdoc;
 
-		del_mtd_device(mtd);
+		mtd_device_unregister(mtd);
 
 		iounmap(this->virtadr);
 		kfree(this->chips);