drm/radeon/si: tell dpm there is a display connected

On SI asics, the SMC will automatically force the performance
level to the lowest level if there are no displays active.  This
prevents automatic performance scaling on PowerXpress systems or
for offscreen rendering or compute when displays are disabled.

Going forward, it would be best to dynamically change this, but
for now leave scaling enabled.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=69395

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/si_dpm.c

@@ -3589,7 +3589,12 @@ static void si_program_display_gap(struct radeon_device *rdev)
 		WREG32(DCCG_DISP_SLOW_SELECT_REG, tmp);
 	}
 
-	si_notify_smc_display_change(rdev, rdev->pm.dpm.new_active_crtc_count > 0);
+	/* Setting this to false forces the performance state to low if the crtcs are disabled.
+	 * This can be a problem on PowerXpress systems or if you want to use the card
+	 * for offscreen rendering or compute if there are no crtcs enabled.  Set it to
+	 * true for now so that performance scales even if the displays are off.
+	 */
+	si_notify_smc_display_change(rdev, true /*rdev->pm.dpm.new_active_crtc_count > 0*/);
 }
 
 static void si_enable_spread_spectrum(struct radeon_device *rdev, bool enable)