This adds support for the nRF51 chip on the board.
If you'd like to run Zephyr on the STM32F4 chip on Carbon, you need to
use the 96b_carbon board instead.
The current SPI Bluetooth protocol only uses 5 wires, so we use the
remaining pin as UART TX.
Signed-off-by: Ricardo Salveti <ricardo.salveti@linaro.org>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Ricard Salveti