Qualcomm Atheros IPQ4019 TLMM block

This is the Top Level Mode Multiplexor block found on the Qualcomm IPQ8019
platform, it provides pinctrl, pinmux, pinconf, and gpiolib facilities.

Required properties:
- compatible: "qcom,ipq4019-pinctrl"
- reg: Should be the base address and length of the TLMM block.
- interrupts: Should be the parent IRQ of the TLMM block.
- interrupt-controller: Marks the device node as an interrupt controller.
- #interrupt-cells: Should be two.
- gpio-controller: Marks the device node as a GPIO controller.
- #gpio-cells : Should be two.
                The first cell is the gpio pin number and the
                second cell is used for optional parameters.

Please refer to ../gpio/gpio.txt and ../interrupt-controller/interrupts.txt for
a general description of GPIO and interrupt bindings.

Please refer to pinctrl-bindings.txt in this directory for details of the
common pinctrl bindings used by client devices, including the meaning of the
phrase "pin configuration node".

The pin configuration nodes act as a container for an abitrary number of
subnodes. Each of these subnodes represents some desired configuration for a
pin, a group, or a list of pins or groups. This configuration can include the
mux function to select on those pin(s)/group(s), and various pin configuration
parameters, such as pull-up, drive strength, etc.

The name of each subnode is not important; all subnodes should be enumerated
and processed purely based on their content.

Each subnode only affects those parameters that are explicitly listed. In
other words, a subnode that lists a mux function but no pin configuration
parameters implies no information about any pin configuration parameters.
Similarly, a pin subnode that describes a pullup parameter implies no
information about e.g. the mux function.


The following generic properties as defined in pinctrl-bindings.txt are valid
to specify in a pin configuration subnode:
 pins, function, bias-disable, bias-pull-down, bias-pull,up, drive-strength.

Non-empty subnodes must specify the 'pins' property.
Note that not all properties are valid for all pins.


Valid values for qcom,pins are:
  gpio0-gpio99
    Supports mux, bias and drive-strength

Valid values for qcom,function are:
aud_pin, audio_pwm, blsp_i2c0, blsp_i2c1, blsp_spi0, blsp_spi1, blsp_uart0,
blsp_uart1, chip_rst, gpio, i2s_rx, i2s_spdif_in, i2s_spdif_out, i2s_td, i2s_tx,
jtag, led0, led1, led2, led3, led4, led5, led6, led7, led8, led9, led10, led11,
mdc, mdio, pcie, pmu, prng_rosc, qpic, rgmii, rmii, sdio, smart0, smart1,
smart2, smart3, tm, wifi0, wifi1

Example:

	tlmm: pinctrl@1000000 {
		compatible = "qcom,ipq4019-pinctrl";
		reg = <0x1000000 0x300000>;

		gpio-controller;
		#gpio-cells = <2>;
		interrupt-controller;
		#interrupt-cells = <2>;
		interrupts = <0 208 0>;

		serial_pins: serial_pinmux {
			mux {
				pins = "gpio60", "gpio61";
				function = "blsp_uart0";
				bias-disable;
			};
		};
	};