ARM: dts: rockchip: add rk3128 soc dtsi

Add basic rk3128 support.

Features:
  Quad-core ARM Cortex-A7MP Core processor
  Clock & reset unit
  Power management unit
  Interrupt controller
  DMAC
  6x 64 bits Timers
  4x PWMs
  1x 32 bits watchdog

Internal memory:
  Internal BootRom
  Internal SRAM 8KB

External memory:
  Dynamic Memory Interface (DDR3/DDR3L/LPDDR2)
  Nand Flash Interface
  eMMC Interface
  SD/MMC Interface

Connectivity:
  SDIO interface
  SPI Controller
  3x UART controller
  4x I2C controllers
  4x groups of GPIO (GPIO0~GPIO3), 32 GPIOs per group
  USB Host2.0
  USB OTG2.0

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/b7bac0b3-3c91-1026-d435-6b5e9d6492f3@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>