ASoC: samsung: i2s: mark OF related data as maybe unused

The driver can be compile tested with !CONFIG_OF making certain data
unused:

  sound/soc/samsung/i2s.c:1646:42: warning: ‘i2sv5_dai_type_i2s1’ defined but not used [-Wunused-const-variable=]
  sound/soc/samsung/i2s.c:1639:42: warning: ‘i2sv7_dai_type’ defined but not used [-Wunused-const-variable=]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
Link: https://lore.kernel.org/r/20201125164452.89239-36-krzk@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/samsung/i2s.c

@@ -1621,28 +1621,28 @@ static const struct samsung_i2s_dai_data i2sv3_dai_type = {
 	.i2s_variant_regs = &i2sv3_regs,
 };
 
-static const struct samsung_i2s_dai_data i2sv5_dai_type = {
+static const struct samsung_i2s_dai_data i2sv5_dai_type __maybe_unused = {
 	.quirks = QUIRK_PRI_6CHAN | QUIRK_SEC_DAI | QUIRK_NEED_RSTCLR |
 			QUIRK_SUPPORTS_IDMA,
 	.pcm_rates = SNDRV_PCM_RATE_8000_96000,
 	.i2s_variant_regs = &i2sv3_regs,
 };
 
-static const struct samsung_i2s_dai_data i2sv6_dai_type = {
+static const struct samsung_i2s_dai_data i2sv6_dai_type __maybe_unused = {
 	.quirks = QUIRK_PRI_6CHAN | QUIRK_SEC_DAI | QUIRK_NEED_RSTCLR |
 			QUIRK_SUPPORTS_TDM | QUIRK_SUPPORTS_IDMA,
 	.pcm_rates = SNDRV_PCM_RATE_8000_96000,
 	.i2s_variant_regs = &i2sv6_regs,
 };
 
-static const struct samsung_i2s_dai_data i2sv7_dai_type = {
+static const struct samsung_i2s_dai_data i2sv7_dai_type __maybe_unused = {
 	.quirks = QUIRK_PRI_6CHAN | QUIRK_SEC_DAI | QUIRK_NEED_RSTCLR |
 			QUIRK_SUPPORTS_TDM,
 	.pcm_rates = SNDRV_PCM_RATE_8000_192000,
 	.i2s_variant_regs = &i2sv7_regs,
 };
 
-static const struct samsung_i2s_dai_data i2sv5_dai_type_i2s1 = {
+static const struct samsung_i2s_dai_data i2sv5_dai_type_i2s1 __maybe_unused = {
 	.quirks = QUIRK_PRI_6CHAN | QUIRK_NEED_RSTCLR,
 	.pcm_rates = SNDRV_PCM_RATE_8000_96000,
 	.i2s_variant_regs = &i2sv5_i2s1_regs,