ASoC: sta529: Remove superfluous const

As SOC_ENUM_SINGLE_DECL() itself contains const modifier now, we can
reduce const from its users.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/sta529.c

@@ -141,7 +141,7 @@ static const char *pwm_mode_text[] = { "Binary", "Headphone", "Ternary",
 
 static const DECLARE_TLV_DB_SCALE(out_gain_tlv, -9150, 50, 0);
 static const DECLARE_TLV_DB_SCALE(master_vol_tlv, -12750, 50, 0);
-static const SOC_ENUM_SINGLE_DECL(pwm_src, STA529_FFXCFG1, 4, pwm_mode_text);
+static SOC_ENUM_SINGLE_DECL(pwm_src, STA529_FFXCFG1, 4, pwm_mode_text);
 
 static const struct snd_kcontrol_new sta529_snd_controls[] = {
 	SOC_DOUBLE_R_TLV("Digital Playback Volume", STA529_LVOL, STA529_RVOL, 0,