soc: arm: st: add stm32l4r9xx support

Add support for ST stm32l4r9xx System-on-Chip.

See http://www.st.com/en/microcontrollers/stm32l4r9-s9.html
for more details.

Signed-off-by: Armando Visconti <armando.visconti@st.com>
4 files changed