SQL Query
update ubbt_FORUM_PERMISSIONS
set POLLS_IN_TOPICS=1
where GROUP_ID <> 5

If you want them to be able to make polls in replies as well:

SQL Query
update ubbt_FORUM_PERMISSIONS
set POLLS_IN_TOPICS=1
POLLS_IN_REPLIES=1
where GROUP_ID <> 5

Anyone logged in while this query is done, will need to logout and then log back in, in order to get the new permission.