powerpc/85xx: Add TWR-P10xx board support

TWR-P1025 Specification:
-----------------------
Memory subsystem:
   512MB DDR3 (on board DDR)
   64Mbyte 16bit NOR flash
   One microSD Card slot

Ethernet:
   eTSEC1: Connected to Atheros AR8035 GETH PHY
   eTSEC3: Connected to Atheros AR8035 GETH PHY

UART:
   Two UARTs are routed to the FDTI dual USB to RS232 convertor

USB: Two USB2.0 Type A ports

I2C:
   AT24C01B 1K Board EEPROM (8 bit address)

QUICC Engine:
   Connected to DP83849i PHY supply two 10/100M ethernet ports
   QE UART for RS485 or RS232

PCIE:
   One mini-PCIE slot

Signed-off-by: Michael Johnston <michael.johnston@freescale.com>
Signed-off-by: Xie Xiaobo <X.Xie@freescale.com>
[yorksun: Fixup include/configs/p1_twr.h]
Signed-off-by: York Sun <yorksun@freescale.com>