[aml] Switch xbmcpvr to use upstream repo

Use the latest commit (version 1.6.12+) from the 'frodo' branch of fetzerch/xbmc-pvr-addons in order to get fixes for mythtv-cmyth needed to fix compatibility with MythTV 0.27.  All of the other plugins in this repo appear to be identical to those in Pivosgroup/pivos-pvr-addons.
[aml] Revert to kernel 2.6.34

2.6.34.7 made no noticeable improvements.  Keeping the changes to the
packaging scripts in case we have a reason to try upgrading again in the
future.