Microchip PIC32 Quad SPI controller
-----------------------------------
Required properties:
- compatible: Should be "microchip,pic32mzda-sqi".
- reg: Address and length of SQI controller register space.
- interrupts: Should contain SQI interrupt.
- clocks: Should contain phandle of two clocks in sequence, one that drives
clock on SPI bus and other that drives SQI controller.
- clock-names: Should be "spi_ck" and "reg_ck" in order.