video: add support of STM32 MIPI DSI controller driver

Add the STM32 DSI controller driver that uses the Synopsys DesignWare
MIPI DSI host controller bridge.

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
diff --git a/drivers/video/stm32/Makefile b/drivers/video/stm32/Makefile
index 7297e5f..f8b42d1 100644
--- a/drivers/video/stm32/Makefile
+++ b/drivers/video/stm32/Makefile
@@ -6,3 +6,4 @@
 #          Yannick Fertre <yannick.fertre@st.com>
 
 obj-${CONFIG_VIDEO_STM32} = stm32_ltdc.o
+obj-${CONFIG_VIDEO_STM32_DSI} += stm32_dsi.o