Jetson orig Nano use MIPI connect to camera without IIC

that’s correct, it’s mentioned by Camera API Matrix.

BTW,
you may try with nvv4l2camerasrc plugin as an alternative way to test your YUV camera stream via gst pipeline.
for instance, $ gst-launch-1.0 nvv4l2camerasrc device=/dev/video1 ! 'video/x-raw(memory:NVMM),format=UYVY,width=1920,height=1080,framerate=30/1 ! nvvidconv ! xvimagesink