ASoC: soc-component: fix undefined reference to __ffssi2

microblaze-linux-gcc (GCC) 9.3.0 complains about missing __ffssi2
symbol while using __builtin_ffs at runtime.

This is because arch/h8300 is compiled with -fno-builtin option.

so fallback and use kernel ffs() instead to all the arch builds happy!

Fixes: 1da0b989 ("ASoC: soc-component: add snd_soc_component_read/write_field()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210129100539.23459-1-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-component.c

@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <sound/soc.h>
+#include <linux/bitops.h>
 
 #define soc_component_ret(dai, ret) _soc_component_ret(dai, __func__, ret)
 static inline int _soc_component_ret(struct snd_soc_component *component,
@@ -43,7 +44,7 @@ static inline int soc_component_field_shift(struct snd_soc_component *component,
 		return 0;
 	}
 
-	return (__builtin_ffs(mask) - 1);
+	return (ffs(mask) - 1);
 }
 
 /*