WIP: DVB-C support

[Max Laier]

Okay ... small update in case anyone is interested:

  http://people.freebsd.org/~mlaier/mantis.20100111.tgz

this now works on amd64 thanks to the new facilities that came of the NVidia 
amd64 support efforts.  It turns out that the userland buffer mapping was not 
working as well as it should have.  Read: It was broken with bounce buffers.  
Instead I moved to a kernel buffer that can be mapped to userland instead.  
This, however, is rather heavy on KVA space (16MB+some in the default 
configuration), but it works for me[tm].

The userland tools still don't do anything useful.  vp2040 dumps the 
transponder @362Mhz/QAM256 (where I have a HD program to test with).  You can 
alter this to your provider by looking for tda10023_set_params in the source. 
multimedia/vlc is happy to play the dump (most of the times).

"new_cap -s" lets you scan for available programs in the frequencies provided 
in "freq.de" which list all the DVB-C frequencies in germany, at the moment.

In any case ... I'll be hacking on this some more and hope to have a proper 
DVB-C PVR suite, if anyone is interested in joining the effort - please let me 
know!

Regards,
--
  Max