ASoC: DMI long name - avoid to add board name if matches with product name

Current code:

  LENOVO-20QE000VMC-ThinkPadX1Carbon7th-20QE000VMC

With the patch:

  LENOVO-20QE000VMC-ThinkPadX1Carbon7th

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20191120174435.30920-2-perex@perex.cz
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -1798,7 +1798,8 @@ int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 
 	board = dmi_get_system_info(DMI_BOARD_NAME);
 	if (board && is_dmi_valid(board)) {
-		append_dmi_string(card, board);
+		if (!product || strcasecmp(board, product))
+			append_dmi_string(card, board);
 	} else if (!product) {
 		/* fall back to using legacy name */
 		dev_warn(card->dev, "ASoC: no DMI board/product name!\n");