drm/nouveau/therm: rework thermal table parsing

As an accident, it should also fix temperature reading on nv4x.

v2: introduce nvbios_therm_entry as advised by darktama

Signed-off-by: Martin Peres <martin.peres@labri.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
6 files changed