spi: Document the STM32 SPI bindings

This patch adds the documentation of device tree bindings
for the STM32 SPI controller.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Amelie Delaunay 2017-06-21 16:32:05 +02:00 • committed by Mark Brown
commit 82a29bf995