feat(fdts): add DDR4 files for STM32MP2

These DT files will be used by STM32MP2 boards. They embed DDR parameters
for DDR4 2x8Gb 2*16bits, at 800MHz or 1200MHz.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: Iec73f9c5028f897624125082bdb591274aad3afc
2 files changed