powerpc/mpc85xx: Add T2080/T2081 SoC support

Add support for Freescale T2080/T2081 SoC.

T2080 includes the following functions and features:
- Four dual-threads 64-bit Power architecture e6500 cores, up to 1.8GHz
- 2MB L2 cache and 512KB CoreNet platform cache (CPC)
- Hierarchical interconnect fabric
- One 32-/64-bit DDR3/3L SDRAM memory controllers with ECC and interleaving
- Data Path Acceleration Architecture (DPAA) incorporating acceleration
- 16 SerDes lanes up to 10.3125 GHz
- 8 mEMACs for network interfaces (four 1Gbps MACs and four 10Gbps/1Gbps MACs)
- High-speed peripheral interfaces
  - Four PCI Express controllers (two PCIe 2.0 and two PCIe 3.0 with SR-IOV)
  - Two Serial RapidIO 2.0 controllers/ports running at up to 5 GHz
- Additional peripheral interfaces
  - Two serial ATA (SATA 2.0) controllers
  - Two high-speed USB 2.0 controllers with integrated PHY
  - Enhanced secure digital host controller (SD/SDHC/SDXC/eMMC)
  - Enhanced serial peripheral interface (eSPI)
  - Four I2C controllers
  - Four 2-pin UARTs or two 4-pin UARTs
  - Integrated Flash Controller supporting NAND and NOR flash
- Three eight-channel DMA engines
- Support for hardware virtualization and partitioning enforcement
- QorIQ Platform's Trust Architecture 2.0

Differences between T2080 and T2081:
  Feature               T2080 T2081
  1G Ethernet numbers:  8     6
  10G Ethernet numbers: 4     2
  SerDes lanes:         16    8
  Serial RapidIO,RMan:  2     no
  SATA Controller:      2     no
  Aurora:               yes   no
  SoC Package:          896-pins 780-pins

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