Merge tag 'fixes-for-v2020.07' of https://gitlab.denx.de/u-boot/custodians/u-boot-video

- fix logo on mx6ul_14x14_evk with DM_VIDEO enabled
- fix banner string overwriting the logo on small displays
- fix splash warning when building for ARM64
- fix STM32 DSI driver to probe only on supported hardware
- fix memory corruption with DSI panel drivers