ufs: Correct the UFS terminlogy

UFS stands for Universal Flash Storage, not Subsytem.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>
diff --git a/drivers/ufs/ufs-uclass.c b/drivers/ufs/ufs-uclass.c
index ceea30c..ffae811 100644
--- a/drivers/ufs/ufs-uclass.c
+++ b/drivers/ufs/ufs-uclass.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /**
- * ufs-uclass.c - Universal Flash Subsystem (UFS) Uclass driver
+ * ufs-uclass.c - Universal Flash Storage (UFS) Uclass driver
  *
  * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
  */