Embedded Power Measurement(EPM) using Cypress Progammable System on a chip (PSOC)

The EPM using the PSoC5 is used by clients to measure on target power
measurement on supported channels. The PSoC5 is a microcontroller
that is communicated over the SPI from the MSM. Primary configuration
supports upto 31 channels and the scope of the driver is to support
userspace clients.

EPM node

Required properties:
- compatible : should be "cy,epm-adc-cy8c5568lti-114" for EPM using PSoC5.
- reg : chip select for the device.
- interrupt-parent : should be phandle of the interrupt controller
		     servicing the interrupt for this device.
- spi-max-frequency : existing support is set for 960kHz.
- qcom,channels : The number of voltage and current channels that
		  are supported.
- qcom,gain : The gain for each of the supported channels.
- qcom,rsense : The rsense value for each channel. The current channels
		rsense values units are in milliohms. The voltage channels
		rsense value is 1.
- qcom,channel-type : Bitmak of channels to set as voltage and current.
		      These are platform dependent and the appropriate scaling
		      functions are used for returning voltage and current.
- qcom,<gpio-name>-gpio : Handle to the GPIO node, see "gpios property" in
		Documentation/devicetree/bindings/gpio/gpio.txt.
  "gpio-name" can be "epm-enable" which is the EPM global enable GPIO for powering up the PSoC.