* Bluetooth Controller
Bluetooth controller communicates with the Bluetooth Host using HCI Transport
layer. HCI Transport layer can be based on UART or USB serial communication
protocol.

Required properties:
- compatible: "qcom,<chip>"
	chip: Should be set to one of the following:
		qcom,qca6174
		qcom,wcn3990
		qcom,qca6390
		qcom,qca6490
                qcom,kiwi
	- qcom,bt-reset-gpio: GPIO pin to bring BT Controller out of reset

Optional properties:
	-	qcom,xo-clk-gpio: GPIO for enabling clock at bootstrap
	- qcom,bt-vdd-pa-supply: Bluetooth VDD PA regulator handle
	- qcom,bt-vdd-io-supply: Bluetooth VDD IO regulator handle
	- qcom,bt-vdd-ldo-supply: Bluetooth VDD LDO regulator handle. Kept under
		optional parameters as some of the chipsets doesn't require ldo
		or it may use from same vddio.
	- qcom,bt-vdd-xtal-supply: Bluetooth VDD XTAL regulator handle
	- qcom,bt-vdd-core-supply: Bluetooth VDD CORE regulator handle
	- qcom,bt-vdd-asd-supply: Bluetooth VDD regulator handle for antenna switch
	- reg: Memory regions defined as starting address and size
	- reg-names: Names of the memory regions defined in reg entry
    diversity.
	- qcom,bt-chip-pwd-supply: Chip power down gpio is required when bluetooth
		module and other modules like wifi co-exist in a singe chip and
		shares a common gpio to bring chip out of reset.
  - qcom,<supply>-config: Specifies voltage/current levels for supply. Should specified
                          in pairs (min, max), units uV.  There can be optional
                          load in curr, unit uA. Last entry specifies if the retention
                          mode is supported for the regulator.
  - mboxes: Specifies mbox channel data for AOP messaging
  - qcom,vreg_ipa: Specifies Voltage regulator used for QCA6490 Internal Power
                   Amp config

Example:
	bluetooth: bt_qca6490 {
		compatible = "qcom,qca6390", "qcom,qca6490";
		pinctrl-names = "default";
		pinctrl-0 = <&bt_en_sleep>;
		qcom,bt-reset-gpio = <&tlmm 81 0>; /* BT_EN */
		qcom,wl-reset-gpio = <&tlmm 80 0>; /* WL_EN */
		qcom,bt-sw-ctrl-gpio = <&tlmm 82 0>; /* SW_CTRL */
		qcom,bt-xo-clk-gpio = <&tlmm 204 0>; /* XO */
		qcom,bt-vdd-aon-supply = <&S11B>;
		qcom,bt-vdd-dig-supply = <&S11B>;
		qcom,bt-vdd-rfa1-supply = <&S1C>;
		qcom,bt-vdd-rfa2-supply = <&S12B>;
		qcom,bt-vdd-asd-supply = <&L7E>;

		qcom,bt-vdd-aon-config = <966000 966000 0  1>;
		qcom,bt-vdd-dig-config = <966000 966000 0  1>;
		qcom,bt-vdd-rfa1-config = <1880000 1880000 0  1>;
		qcom,bt-vdd-rfa2-config = <1350000 1350000 0  1>;
		qcom,bt-vdd-asd-config = <2800000 2800000 0  1>;
	};