Revert "drm/radeon: dont switch vt on suspend"

Fixes distorted colors on some cards on resume from suspend.

This reverts commit b9729b17

.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98832
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=99163
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=107001
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org