ASoC: Only restore non-default registers for WM8731

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/codecs/wm8731.c

@@ -456,6 +456,9 @@ static int wm8731_resume(struct platform_device *pdev)
 
 	/* Sync reg_cache with the hardware */
 	for (i = 0; i < ARRAY_SIZE(wm8731_reg); i++) {
+		if (cache[i] == wm8731_reg[i])
+			continue;
+
 		data[0] = (i << 1) | ((cache[i] >> 8) & 0x0001);
 		data[1] = cache[i] & 0x00ff;
 		codec->hw_write(codec->control_data, data, 2);