drm/msm/hdmi: drop empty bridge callbacks

Drop empty callbacks msm_hdmi_bridge_enable() and
msm_hdmi_bridge_disable().

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/489707/
Link: https://lore.kernel.org/r/20220616085054.432317-1-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>