ubuntu: enable kernel debugfs under /sys/kernel/debug

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>

06_generate_ubuntu_root.sh

@@ -29,6 +29,7 @@ mkdir -p ./ignore/.root/boot/firmware/ || true
 
 echo '/dev/mmcblk0p2  /boot/firmware/ auto  defaults  0  2' >> ./ignore/.root/etc/fstab
 echo '/dev/mmcblk0p3  /  auto  errors=remount-ro  0  1' >> ./ignore/.root/etc/fstab
+echo 'debugfs  /sys/kernel/debug  debugfs  mode=755,uid=root,gid=gpio,defaults  0  0' >> ./ignore/.root/etc/fstab
 
 rm -rf ./ignore/.root/usr/lib/systemd/system/bb-usb-gadgets.service || true
 rm -rf ./ignore/.root/usr/lib/systemd/system/grow_partition.service || true