drm/atomic-helper: Change parameter name of disable_outputs()

drm/atomic-helper: Change parameter name of disable_outputs()

disable_outputs() disables all connectors and CRTCs affected by a
commit. It takes the drm_atomic_state being committed as a parameter.

However, that parameter name is called as old_state, which is pretty
confusing. Let's rename that variable as state.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250213-bridge-connector-v3-11-e71598f49c8f@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>