drm/radeon: adjust TN dpm parameters for stability (v2)

Adjust some of the TN dpm settings for stability.  Enabling
these features causes hangs and other stability problems
on certain boards.

v2: leave uvd dpm enabled

Bug:
https://bugzilla.kernel.org/show_bug.cgi?id=63101

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/radeon/trinity_dpm.c

@@ -1873,9 +1873,9 @@ int trinity_dpm_init(struct radeon_device *rdev)
 	pi->enable_sclk_ds = true;
 	pi->enable_gfx_power_gating = true;
 	pi->enable_gfx_clock_gating = true;
-	pi->enable_mg_clock_gating = true;
-	pi->enable_gfx_dynamic_mgpg = true; /* ??? */
-	pi->override_dynamic_mgpg = true;
+	pi->enable_mg_clock_gating = false;
+	pi->enable_gfx_dynamic_mgpg = false;
+	pi->override_dynamic_mgpg = false;
 	pi->enable_auto_thermal_throttling = true;
 	pi->voltage_drop_in_dce = false; /* need to restructure dpm/modeset interaction */
 	pi->uvd_dpm = true; /* ??? */