drm/radeon: Turn off CRTCs on driver unload

radeon leaks a runtime pm ref if at least one CRTC is enabled on unload.
The ref is taken by radeon_crtc_set_config() and held as long as a CRTC
is in use. Fix by turning off all CRTCs on unload.

Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/f706b9db319e2bdaf153966a2b95a5d80f67e09b.1465392124.git.lukas@wunner.de

drivers/gpu/drm/radeon/radeon_display.c

@@ -1711,6 +1711,7 @@ void radeon_modeset_fini(struct radeon_device *rdev)
 		radeon_afmt_fini(rdev);
 		drm_kms_helper_poll_fini(rdev->ddev);
 		radeon_hpd_fini(rdev);
+		drm_crtc_force_disable_all(rdev->ddev);
 		drm_mode_config_cleanup(rdev->ddev);
 		rdev->mode_info.mode_config_initialized = false;
 	}