ASoC: sti: set player private data

Set substream player private data.
substream player private data is used in uni_player_irq_handler to lock,
stop & unlock the stream when interrupt indicates underflow/overflow.
If not set, then segmentation fault occurs.
Signed-off-by: Moise Gergaud <moise.gergaud@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sti/uniperif_player.c

@@ -669,6 +669,7 @@ static int uni_player_startup(struct snd_pcm_substream *substream,
 {
 	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
 	struct uniperif *player = priv->dai_data.uni;
+	player->substream = substream;
 
 	player->clk_adj = 0;
 
@@ -950,6 +951,8 @@ static void uni_player_shutdown(struct snd_pcm_substream *substream,
 	if (player->state != UNIPERIF_STATE_STOPPED)
 		/* Stop the player */
 		uni_player_stop(player);
+
+	player->substream = NULL;
 }
 
 static int uni_player_parse_dt_clk_glue(struct platform_device *pdev,