ASoC: sglt5000: Provide the reg_stride field

sgtl5000 has 16-bit registers, and only even numbers are valid for its registers
addresses.

Let regmap knows about this feature by specifying the 'reg_stride' field, so
that it can access only the valid registers.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

sound/soc/codecs/sgtl5000.c

@@ -1470,6 +1470,7 @@ static struct snd_soc_codec_driver sgtl5000_driver = {
 static const struct regmap_config sgtl5000_regmap = {
 	.reg_bits = 16,
 	.val_bits = 16,
+	.reg_stride = 2,
 
 	.max_register = SGTL5000_MAX_REG_OFFSET,
 	.volatile_reg = sgtl5000_volatile,