driconf: Add option definitions to source file, not generated target

driconf: Add option definitions to source file, not generated target

For the last two most-recently-added driconf options, their definition was
manually added to options.h, a file which is intended to be automatically
generated, (as part of support for translated driconf option
descriptions). This means that these options would be eliminated if the
generation step were performed again.

Fix this by correctly adding the definitions of these options to t_options.h,
(the file used as input to the generator), and not the options.h file, which
is generated.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>