Qualcomm GPIO Flash Leds

Qualcomm GPIO flash LEDs driver is used for
controlling flash LEDs that are connected with 2 GPIOs.  The 2 GPIOs are name
flash_en and flash now.


The flash LEDs has torch mode and flash mode. The flash mode is used for camera.
The torch mode is used for torch.


Required properties for each node:
- compatible        : should be "qcom,leds-gpio-flash"
- qcom,flash-en     : the GPIO pin number of flash-en function
- qcom,flash-now    : the GPIO pin number of flash-now function
- linux,name        : name of the led that is used in led framework
- linux,default-trigger : name of the led trigger event
- qcom,op-seq       : GPIO config name
- clocks            : A list of clk correspondence with the gpio pinfunc,
  it is an optional property, it is needed when the flash need use clk
  waveform to driver, and rcg clk is also optional, it is needed when
  the used clk can't configure the duty cycle, we use the parent clk to
  configure the duty cycle.
- clock-names       : Names of the clocks in 1-1 correspondence with the
  "clocks" property.
- qcom,duty-cycle   : It is used to configure the duty cycle in clk mode.
- qcom,clk-freq     : Frequence of clk
- qcom,torch-seq-val: GPIO config value for torch mode
- qcom,flash-seq-val: GPIO config value for flash mode
- pinctrl-names     : pinctrl name
- pinctrl-0         : default gpio stats

No other optional properties for it.

Example:

	flashlight {
		compatible = "leds-gpio-flash";
		status = "okay";
		pinctrl-names = "flash_default";
		pinctrl-0 = <&flash_default>;
		qcom,flash-en = <&msmgpio 31 0>;
		qcom,flash-now = <&msmgpio 32 0>;
		qcom,op-seq = "flash_en", "flash_now";
		clocks = <&clock_gcc clk_camss_gp0_clk>,
			<&clock_gcc clk_camss_gp0_clk_src>,
			<&clock_gcc clk_camss_gp1_clk>,
			<&clock_gcc clk_camss_gp1_clk_src>;
		clock-names = "flash_en_clk", "flash_en_duty_cycle_clk",
			"flash_now_clk", "flash_now_duty_cycle_clk";
		qcom,duty-cycle = <40 30>;
		qcom,clk-freq = <150000 150000>;
		qcom,torch-seq-val = <1, 0>;
		qcom,flash-seq-val = <0, 1>;
		linux,name = "flashlight";
		linux,default-trigger = "flashlight-trigger";
	};
