drm/i2c: tda998x: don't freeze the system at audio startup time

This patch prevents the system to be freezed at audio startup time,
replacing mdelay by msleep.

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/i2c/tda998x_drv.c

@@ -681,7 +681,7 @@ tda998x_configure_audio(struct tda998x_priv *priv,
 	reg_write_range(priv, REG_CH_STAT_B(0), buf, 4);
 
 	tda998x_audio_mute(priv, true);
-	mdelay(20);
+	msleep(20);
 	tda998x_audio_mute(priv, false);
 
 	/* Write the audio information packet */