This commit adds device tree files supporting
SBC from Seeed Studio based on STM32MP157C.
This works with generic stm32mp1 config.
Right now only booting from SD card is supported.
Signed-off-by: Marcin Sloniewski <marcin.sloniewski@gmail.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
