clk: clk_stm32f: Add DSI clock support

DSI clock is available on STM32F769-disco and
STM32F469-disco board.

Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
2 files changed