drm/bridge: aux-hpd: fix OF node leaks

The two device node references taken during allocation need to be
dropped when the auxiliary device is freed.

Fixes: 6914968a

 ("drm/bridge: properly refcount DT nodes in aux bridge drivers")
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20240217150228.5788-2-johan+linaro@kernel.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-2-johan+linaro@kernel.org