drm/msm/dpu: drop obsolete INTF_EDP comment

drm/msm/dpu: drop obsolete INTF_EDP comment

DPU driver never supported INTF_EDP, so let's drop the obsolete comment.
If at some point 8x74/8x84's INTF_EDP is ported to DPU driver,
corresponding handling will have to be ported too. Until that time, the
comment serves no purpose.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/475557/
Link: https://lore.kernel.org/r/20220222062246.242577-4-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>