1. apply the orin-hdmi-support-pinmux.patch for mb1-bct 
2. use the new hdmi dcb file 'tegra234-dcb-p3701-0000-a02-p3737-0000-a01-hdmi-4-ga5.0.2.dtsi' 
3. apply the kernel hdmi hotplug patch 0001-orin-hdmi-hotplug-support-kernel-dts.patch
4. rebuilt the kernel dtb and "reflash the image"  //Note : make sure 'reflash' the image, no substitute dtb in exlinux!!