drm/nouveau/gm107: add voltage control using the new gk104 volt class
drm/nouveau/gm107: add voltage control using the new gk104 volt class

Let's ignore the other desktop Maxwells until I get my hands on one and confirm
that we still can change the voltage.

Signed-off-by: Martin Peres <f078f77bcd6141e84e4eefdc58402db4e0e36622@free.fr>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs