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/cmd/Kconfig b/cmd/Kconfig
index 6470b13..a59c67e 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1536,7 +1536,7 @@
 	  Turndra tsi148 device. See the command help for full details.
 
 config CMD_UFS
-	bool "Enable UFS - Universal Flash Subsystem commands"
+	bool "Enable UFS - Universal Flash Storage commands"
 	depends on UFS
 	help
 	  "This provides commands to initialise and configure universal flash