Add support for AMCC 440SPe CPU based eval board (Yucca).

CHANGELOG

MAKEALL

Makefile

board/amcc/yucca/Makefile

board/amcc/yucca/cmd_yucca.c

board/amcc/yucca/config.mk

board/amcc/yucca/flash.c

board/amcc/yucca/init.S

board/amcc/yucca/u-boot.lds

board/amcc/yucca/u-boot.lds.debug

board/amcc/yucca/yucca.c

board/amcc/yucca/yucca.h

common/cmd_bdinfo.c

common/serial.c

cpu/ppc4xx/405gp_pci.c

cpu/ppc4xx/4xx_enet.c

cpu/ppc4xx/cpu.c

cpu/ppc4xx/interrupts.c

cpu/ppc4xx/miiphy.c

cpu/ppc4xx/serial.c