[PATCH v2 3/7] cmd: fix long text for sound command

[Heinrich Schuchardt]

Make it clear that if only 1 parameter is provided this is the duration.

The ISO symbol for hertz is Hz.

Fixes: c0c88533fffd ("Sound: Add command for audio playback")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
	no change
---
 cmd/sound.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/sound.c b/cmd/sound.c
index f82f2aa670..20ac3f758e 100644
--- a/cmd/sound.c
+++ b/cmd/sound.c
@@ -86,5 +86,5 @@ U_BOOT_CMD(
 	sound, 4, 1, do_sound,
 	"sound sub-system",
 	"init - initialise the sound driver\n"
-	"sound play [len] [freq] - play a sound for len ms at freq hz\n"
+	"sound play [len [freq]] - play a sound for len ms at freq Hz\n"
 );
-- 
2.37.2