ASoC: rt5660: enable MCLK detection

BugLink: http://bugs.launchpad.net/bugs/1657674

There is a power saving mechanism in rt5660. It will turn off some
unused power when MCLK is not present. We call that "MCLK detection"
and it should be enabled by default.
Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit d01580c3)
Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

sound/soc/codecs/rt5660.c

@@ -1311,6 +1311,10 @@ static int rt5660_i2c_probe(struct i2c_client *i2c,
 	if (ret != 0)
 		dev_warn(&i2c->dev, "Failed to apply regmap patch: %d\n", ret);
 
+	regmap_update_bits(rt5660->regmap, RT5660_GEN_CTRL1,
+		RT5660_AUTO_DIS_AMP | RT5660_MCLK_DET | RT5660_POW_CLKDET,
+		RT5660_AUTO_DIS_AMP | RT5660_MCLK_DET | RT5660_POW_CLKDET);
+
 	if (rt5660->pdata.dmic1_data_pin) {
 		regmap_update_bits(rt5660->regmap, RT5660_GPIO_CTRL1,
 			RT5660_GP1_PIN_MASK, RT5660_GP1_PIN_DMIC1_SCL);

sound/soc/codecs/rt5660.h

@@ -810,6 +810,9 @@
 /* General Control 1 (0xfa) */
 #define RT5660_PWR_VREF_HP			(0x1 << 11)
 #define RT5660_PWR_VREF_HP_SFT			11
+#define RT5660_AUTO_DIS_AMP			(0x1 << 6)
+#define RT5660_MCLK_DET				(0x1 << 5)
+#define RT5660_POW_CLKDET			(0x1 << 1)
 #define RT5660_DIG_GATE_CTRL			(0x1)
 #define RT5660_DIG_GATE_CTRL_SFT		0