[osg-submissions] Minor spelling fix

[Paul Martz]

Actually, NVIDIA's web page says that the preferred ASCII representation of
their name is "NVIDIA" (all caps). (Well, at least it used to say this back
about 8 or 9 years ago -- can't find it right now.)
   -Paul



> One for the next release ;-)
> 
> NVidea -> NVidia
> (including option --Nvidea)
> 
> Paul
>