This patchset enables USART3 on the 96Boards STM32 Mezzanine.
It is broken out to J10 Grove Connector.
Changes:
- Enabled USART3 in board dts.
- Updated board index.rst with uart pinouts.
- soc dtsi: enabled usart3.
Test: Tested USART3 as console at 115200 baud
Signed-off-by: Sahaj Sarup <sahaj.sarup@linaro.org>