[pvr] re-init pvr manager on wake up
[pvr] always use last played group as current group on startup

This always use the last played group as current group on startup whether or not you enabled the option 'continue last channel on startup'. With it we'll have no difference in behavior.
Merge pull request #5824 from xhaggi/pvr-use-last-played-group-on-startup

[pvr] always use last played group as current group on startup