Add the STM32F2xx SPI device. Signed-off-by: Alistair Francis <alistair@alistair23.me> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 8197811d5c94f814fa67c6a33ca2f7fd0aa97432.1474742262.git.alistair@alistair23.me Signed-off-by: Peter Maydell <peter.maydell@linaro.org>