dt-bindings: stm32: add compatible for syscon

This patch describes syscon DT bindings.

Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed