drm/nouveau/volt/pwm/gk104: fix an off-by-one resulting in the voltage not being set

Reported-by: Ilia Mirkin <[e-mail]>
Signed-off-by: Martin Peres <[e-mail]>

drivers/gpu/drm/nouveau/nvkm/subdev/volt/gk104.c

···
 	duty = (uv - bios->base) * div / bios->pwm_range;
 
 	nvkm_wr32(device, 0x20340, div);
-	nvkm_wr32(device, 0x20344, 0x8000000 | duty);
+	nvkm_wr32(device, 0x20344, 0x80000000 | duty);
 
 	return 0;
 }