Update the Icicle Kit device tree

This series updates the Microchip Icicle Kit device tree by adding a
host of peripherals, and some updates to the memory map. In addition,
the device tree has been split into a third part, which contains "soft"
peripherals that are in the fpga fabric.

Several of the entries are for peripherals that have not get had their
drivers upstreamed, so in those cases the dt bindings are included where
appropriate in order to avoid the many "DT compatible string <x> appears
un-documented" errors.

* palmer/riscv-microchip:
  MAINTAINERS: update riscv/microchip entry
  riscv: dts: microchip: add new peripherals to icicle kit device tree
  riscv: dts: microchip: update peripherals in icicle kit device tree
  riscv: dts: microchip: refactor icicle kit device tree
  riscv: dts: microchip: add fpga fabric section to icicle kit
  riscv: dts: microchip: use clk defines for icicle kit
  dt-bindings: pwm: add microchip corepwm binding
  dt-bindings: gpio: add bindings for microchip mpfs gpio
  dt-bindings: rtc: add bindings for microchip mpfs rtc
  dt-bindings: soc/microchip: add info about services to mpfs sysctrl
  dt-bindings: soc/microchip: update syscontroller compatibles
  dt-bindings: clk: microchip: Add Microchip PolarFire host binding