drm/radeon: rework fbdev handling on chips with no connectors

Move all the logic to radeon_fb.c and add checks to functions
called frome elsewhere.

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=112781

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index a4674bf..a885dae 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -1670,10 +1670,8 @@
 	/* setup afmt */
 	radeon_afmt_init(rdev);
 
-	if (!list_empty(&rdev->ddev->mode_config.connector_list)) {
-		radeon_fbdev_init(rdev);
-		drm_kms_helper_poll_init(rdev->ddev);
-	}
+	radeon_fbdev_init(rdev);
+	drm_kms_helper_poll_init(rdev->ddev);
 
 	/* do pm late init */
 	ret = radeon_pm_late_init(rdev);