Add FEC pin set and mii reset in __mii_init(). Change
legacy flash vendor from 2 to AMD LEGACY (0xFFF0),
change cfi_offset to 0, and change CFG_FLASH_CFI to
CONFIG_FLASH_CFI_LEGACY. Correct M54451EVB and
M54455EVB env settings in configuration file.
Signed-off-by: TsiChung Liew <Tsi-Chung.Liew@freescale.com>