drm/msm: Enable clamp_to_idle for 7c3

This was overlooked.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/511693/
Link: https://lore.kernel.org/r/20221115155535.1615278-1-robdclark@gmail.com