ASoC: rt5645: add device tree support

Modify the RT5645 driver to parse platform data from device tree.
Write a DT binding document to describe those properties.
Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/rt5645.txt

+RT5650/RT5645 audio CODEC
+
+This device supports I2C only.
+
+Required properties:
+
+- compatible : One of "realtek,rt5645" or "realtek,rt5650".
+
+- reg : The I2C address of the device.
+
+- interrupts : The CODEC's interrupt output.
+
+Optional properties:
+
+- hp-detect-gpios:
+  a GPIO spec for the external headphone detect pin. If jd-mode = 0,
+  we will get the JD status by getting the value of hp-detect-gpios.
+
+- realtek,in2-differential
+  Boolean. Indicate MIC2 input are differential, rather than single-ended.
+
+- realtek,dmic1-data-pin
+  0: dmic1 is not used
+  1: using IN2P pin as dmic1 data pin
+  2: using GPIO6 pin as dmic1 data pin
+  3: using GPIO10 pin as dmic1 data pin
+  4: using GPIO12 pin as dmic1 data pin
+
+- realtek,dmic2-data-pin
+  0: dmic2 is not used
+  1: using IN2N pin as dmic2 data pin
+  2: using GPIO5 pin as dmic2 data pin
+  3: using GPIO11 pin as dmic2 data pin
+
+-- realtek,jd-mode : The JD mode of rt5645/rt5650
+   0 : rt5645/rt5650 JD function is not used
+   1 : Mode-0 (VDD=3.3V), two port jack detection
+   2 : Mode-1 (VDD=3.3V), one port jack detection
+   3 : Mode-2 (VDD=1.8V), one port jack detection
+
+Pins on the device (for linking into audio routes) for RT5645/RT5650:
+
+  * DMIC L1
+  * DMIC R1
+  * DMIC L2
+  * DMIC R2
+  * IN1P
+  * IN1N
+  * IN2P
+  * IN2N
+  * Haptic Generator
+  * HPOL
+  * HPOR
+  * LOUTL
+  * LOUTR
+  * PDM1L
+  * PDM1R
+  * SPOL
+  * SPOR
+
+Example:
+
+codec: rt5650@1a {
+	compatible = "realtek,rt5650";
+	reg = <0x1a>;
+	hp-detect-gpios = <&gpio 19 0>;
+	interrupt-parent = <&gpio>;
+	interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
+	realtek,dmic-en = "true";
+	realtek,en-jd-func = "true";
+	realtek,jd-mode = <3>;
+};
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