Try to pull the battery to stop the reboot loop.
Wait a couple of seconds, then reinsert the battery and charge it for some time.

Nevertheless it might be necessary to flash the kernel only to it.
This wiki article explains the procedure http://wiki.maemo.org/Updating_the_t...rt_topic.21.29

Depending on the status of the partitioning, you, may be, will have to start gparted again to correct some things.
Feel free to ask here.