Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index ef4813b..b015b00 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -385,6 +385,8 @@
 
 	/*
 	 * memory management for queue data structures
+	 *
+	 * @td_cache and @ed_cache are %NULL if &usb_hcd.localmem_pool is used.
 	 */
 	struct dma_pool		*td_cache;
 	struct dma_pool		*ed_cache;