These two were already in rc4 (in fact, the only changes since rc3):

$ git log --oneline v4.18-rc3..v4.18-rc4 drivers/gpu/drm/amd/display/amdgpu_dm
413ff0b94248 drm/amd/display: add a check for display depth validity
a6311be8f062 drm/amd/display: adding ycbcr420 pixel encoding for hdmi

So issue is still present :(