ASoC: Disable regmap helpers if regmap is disabled

If regmap is disabled there will be no users of the ASoC regmap helpers.
Furthermore regmap_exit() will no be defined causing the following compile
error:
	sound/soc/soc-core.c: In function 'snd_soc_component_exit_regmap':
	sound/soc/soc-core.c:2645:2: error: implicit declaration of function
		'regmap_exit' [-Werror=implicit-function-declaration]

So disable the helpers if regmap is disabled.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Fixes: 20feb881 ASoC: Add helper functions for deferred regmap setup")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -1286,6 +1286,8 @@ void snd_soc_component_async_complete(struct snd_soc_component *component);
 int snd_soc_component_test_bits(struct snd_soc_component *component,
 	unsigned int reg, unsigned int mask, unsigned int value);
 
+#ifdef CONFIG_REGMAP
+
 void snd_soc_component_init_regmap(struct snd_soc_component *component,
 	struct regmap *regmap);
 void snd_soc_component_exit_regmap(struct snd_soc_component *component);
@@ -1321,6 +1323,8 @@ static inline void snd_soc_codec_exit_regmap(struct snd_soc_codec *codec)
 	snd_soc_component_exit_regmap(&codec->component);
 }
 
+#endif
+
 /* device driver data */
 
 static inline void snd_soc_card_set_drvdata(struct snd_soc_card *card,

sound/soc/soc-core.c

@@ -3661,6 +3661,8 @@ static void snd_soc_component_setup_regmap(struct snd_soc_component *component)
 		component->val_bytes = val_bytes;
 }
 
+#ifdef CONFIG_REGMAP
+
 /**
  * snd_soc_component_init_regmap() - Initialize regmap instance for the component
  * @component: The component for which to initialize the regmap instance
@@ -3696,6 +3698,8 @@ void snd_soc_component_exit_regmap(struct snd_soc_component *component)
 }
 EXPORT_SYMBOL_GPL(snd_soc_component_exit_regmap);
 
+#endif
+
 static void snd_soc_component_add_unlocked(struct snd_soc_component *component)
 {
 	if (!component->write && !component->read) {