So you would like to see your root partiton as exported mount?
You can do that, yes, hewever I am not sure why you would like to do it....
Just change the entry /dev/mmcblk0p1 to /dev/mmcblk0p2 but there are downsides... Doing it thatway means you would need to umount the root partition from the device

And before you try that, HEY, I am KIDDING Ya!
It's not possible unless you mount something else as root before doing it.

There are ways of doing it, though.
For example you could export any given partition as nfs filesystem over the usb connection. (or via wlan, as far as it matters)
That is doable without umounting it on the device.

However to do that you need NFS server on the device.