* Freescale SIUL2 iomux controller

See chapter 20 ("System Integration Unit Lite2 (SIUL2)") in the reference
manual[1].

Based on fsl,imx-pincontrol implementation.

Required properties:
- compatible: "fsl,s32v234-siul2"
- fsl,pins: two integers array, represents a group of pins mux and config
  setting. The format is fsl,pins = <PIN_FUNC_ID CONFIG>
  PIN_FUNC_ID - id of MSCR to be modified
  CONFIG - configuration to be written in the MSCR/IMCR register

  Even though IMCR register should be used as input register, it can be
  set and addressed in the same way as MSCR, only instead of passing the
  IMCR index, IMCR_IDX + 512 is passed[1].

[1] https://www.nxp.com/webapp/Download?colCode=S32V234RM