As the spi flash transfer to multiple parts, it is forgot to add
Atmel AT25DF321 spi flash support, which broken several Atmel EK
boards which this chip. So, add it
Signed-off-by: Bo Shen <voice.shen@atmel.com> Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>