powerpc/t1024rdb: Add T1024 RDB board support

T1024RDB is a Freescale Reference Design Board that hosts the T1024 SoC.

T1024RDB board Overview
-----------------------
- T1024 SoC integrating two 64-bit e5500 cores up to 1.4GHz
- CoreNet fabric supporting coherent and noncoherent transactions with
  prioritization and bandwidth allocation
- 32-/64-bit DDR3L SDRAM memory controller with ECC and interleaving support
- Accelerator: DPAA components consist of FMan, BMan, QMan, DCE and SEC
- Ethernet interfaces:
  - Two 10M/100M/1G RGMII ports on-board
  - one 10Gbps XFI interface
- PCIe: Three PCIe controllers: one PCIe Slot and two Mini-PCIe connectors.
- SerDes: 4 lanes up to 10.3125GHz
- IFC: 128MB NOR Flash, 512MB NAND Flash and CPLD
- eSPI: 64MB N25Q512 SPI flash.
- Deep Sleep power implementaion (wakeup from GPIO/Timer/Ethernet/USB)
- USB: Two  Type-A USB2.0 ports with internal PHY
- eSDHC: Support SD, SDHC, SDXC and MMC/eMMC
- I2C: Four I2C controllers
- UART: Two UART serial ports

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
[York Sun: Fix ft_board_setup() type, fix MAINTAINERS for SECURE_BOOT
	   Fix Kconfig by adding SUPPORT_SPL]
Reviewed-by: York Sun <yorksun@freescale.com>