drm/radeon: fix si_enable_smc_cac() failed issue

Need to set the dte flag on this asic.

Port the fix from amdgpu:
5cb818b8 ("drm/amd/amdgpu: fix si_enable_smc_cac() failed issue")
Reviewed-by: Yong Zhao <yong.zhao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/si_dpm.c

@@ -1958,6 +1958,7 @@ static void si_initialize_powertune_defaults(struct radeon_device *rdev)
 		case 0x682C:
 			si_pi->cac_weights = cac_weights_cape_verde_pro;
 			si_pi->dte_data = dte_data_sun_xt;
+			update_dte_from_pl2 = true;
 			break;
 		case 0x6825:
 		case 0x6827: