ASoC: wm5102: Correct supported channels on trace compressed DAI

The audio trace firmware on wm5102 only supports 4 channels correct
the DAI driver structure to reflect this.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/wm5102.c b/sound/soc/codecs/wm5102.c
index da60e3f..e7fe6b7 100644
--- a/sound/soc/codecs/wm5102.c
+++ b/sound/soc/codecs/wm5102.c
@@ -1872,7 +1872,7 @@
 		.capture = {
 			.stream_name = "Audio Trace CPU",
 			.channels_min = 1,
-			.channels_max = 6,
+			.channels_max = 4,
 			.rates = WM5102_RATES,
 			.formats = WM5102_FORMATS,
 		},