dm: rename DM_TYPE_MQ_REQUEST_BASED to DM_TYPE_REQUEST_BASED

Now that request-based DM is only using blk-mq, there is no need to
differentiate between legacy "rq" and new "mq".  We're back to a single
request-based DM -- and there was much rejoicing!

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 6fb0808..8d93775 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -26,9 +26,8 @@ enum dm_queue_mode {
 	DM_TYPE_NONE		 = 0,
 	DM_TYPE_BIO_BASED	 = 1,
 	DM_TYPE_REQUEST_BASED	 = 2,
-	DM_TYPE_MQ_REQUEST_BASED = 3,
-	DM_TYPE_DAX_BIO_BASED	 = 4,
-	DM_TYPE_NVME_BIO_BASED	 = 5,
+	DM_TYPE_DAX_BIO_BASED	 = 3,
+	DM_TYPE_NVME_BIO_BASED	 = 4,
 };
 
 typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;