drm/nouveau/clk: make therm and volt devices optional

Allow the clock subsystem to operate even if voltage and thermal devices
are not set for the device (for people with watercooling! ;))

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Alexandre Courbot 2014-07-26 18:41:39 +09:00 • committed by Ben Skeggs
commit 2cfd22f473