Automatically generate the hvsupport.html.in file from source files

Automatically generate the hvsupport.html.in file from source files

The hvsupport.html.in file is forever out of date. By annotating
the driver struct tables in each driver with version information,
we can auto-generate the hvsupport.html.in file. Annotating the
drivers will be mandatory for new patches, ensuring hvsupport.html.in
is never out of date again.

* docs/hvsupport.html.in: Delete
* hvsupport.pl: Script to generate hvsupport.html.in
* Makefile.am: Autogenerate hvsupport.html.in