powerpc/t2081qds: Add T2081 QDS board support

T2081 QDS is a high-performance computing evaluation, development and
test platform supporting the T2081 QorIQ Power Architecture processor.

T2081QDS board Overview
-----------------------
- T2081 SoC integrating four 64-bit dual-threads e6500 cores up to 1.8GHz
- 2MB shared L2 and 512KB L3 CoreNet platform cache (CPC)
- CoreNet fabric supporting coherent and noncoherent transactions with
  prioritization and bandwidth allocation
- 32-/64-bit DDR3/DDR3LP SDRAM memory controller with ECC and interleaving
- Ethernet interfaces:
  - Two on-board 10M/100M/1G bps RGMII ports
  - Two 10Gbps XFI with on-board SFP+ cage
  - 1Gbps/2.5Gbps SGMII Riser card
  - 10Gbps XAUI Riser card
- Accelerator:
  - DPAA components consist of FMan, BMan, QMan, PME, DCE and SEC
- SerDes:
  - 8 lanes up to 10.3125GHz
  - Supports SGMII, HiGig, XFI, XAUI and Aurora debug,
- IFC:
  - 512MB NOR Flash, 2GB NAND Flash, PromJet debug port and Qixis FPGA
- eSPI:
  - Three SPI flash (16MB N25Q128A + 16MB EN25S64 + 512KB SST25WF040)
- USB:
  - Two USB2.0 ports with internal PHY (one Type-A + one micro Type mini-AB)
- PCIe:
  - Four PCI Express controllers (two PCIe 2.0 and two PCIe 3.0 with SR-IOV)
- eSDHC:
  - Supports various SD/SDHC/SDXC/eMMC devices with adapter cards and
    voltage translators
- I2C:
  - Four I2C controllers.
- UART:
  - Dual 4-pins UART serial ports

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>