In order to prepare and ease future DT synchronization with kernel
DT, migrate all U-boot specific nodes/properties/addons to
U-boot DT files.
Migrate also DT nodes which are not yet available on kernel DT side
as ethernet, ltdc and qspi nodes.
Fix ethernet_mii pins and add missing qspi_pins for stm32746g-eval
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
