Merge tag 'video-for-2020.01' of https://gitlab.denx.de/u-boot/custodians/u-boot-video

- panel bridge support in stm32 ltdc
- DSI host uclass
- sandbox DSI host uclass test driver and DSI host test
- MIPI DSI helpers
- Synopsys Designware MIPI DSI host bridge driver
- STM32 DSI controller driver
- OTM800A and RM68200 panel support
- DSI host updates for stm32f769 and stm32mp1 dtsi files
- splash screen for stm32f769 and stm32mp1 boards
- stm32 defconfig updates for display support