drm/nouveau/tmr/tu106: initial support

Appears to be compatible with GK20A.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -2478,6 +2478,7 @@ nv166_chipset = {
 	.ibus = gm200_ibus_new,
 	.mc = tu104_mc_new,
 	.pci = gp100_pci_new,
+	.timer = gk20a_timer_new,
 	.top = gk104_top_new,
 };