ASoC: rt5645: add register setting for TDM

We need to set extra register to avoid a recording issue in TDM
mode.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/rt5645.c b/sound/soc/codecs/rt5645.c
index 665f8b6..57afa12 100644
--- a/sound/soc/codecs/rt5645.c
+++ b/sound/soc/codecs/rt5645.c
@@ -2112,8 +2112,11 @@
 	struct snd_soc_codec *codec = dai->codec;
 	unsigned int val = 0;
 
-	if (rx_mask || tx_mask)
+	if (rx_mask || tx_mask) {
 		val |= (1 << 14);
+		snd_soc_update_bits(codec, RT5645_BASS_BACK,
+			RT5645_G_BB_BST_MASK, RT5645_G_BB_BST_25DB);
+	}
 
 	switch (slots) {
 	case 4: