Revert "drm/amd/display: Fix overlay validation by considering cursors"

This reverts commit 33f409e6.

The patch that we are reverting here was originally applied because it
fixes multiple IGT issues and flickering in Android. However, after a
discussion with Sean Paul and Mark, it looks like that this patch might
cause problems on ChromeOS. For this reason, we decided to revert this
patch.

Cc: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Hersen Wu <hersenxs.wu@amd.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Mark Yacoub <markyacoub@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org