drm/bridge-connector: Fix bridge in drm_connector_hdmi_audio_init()

drm/bridge-connector: Fix bridge in drm_connector_hdmi_audio_init()

The bridge used in drm_connector_hdmi_audio_init() does not correctly
point to the required audio bridge, which lead to incorrect audio
configuration input.

Fixes: 231adeda9f67 ("drm/bridge-connector: hook DisplayPort audio support")
Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Link: https://lore.kernel.org/r/20250620011616.118-1-kernel@airkyi.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>