drm/msm/hdmi: fix memory corruption with too many bridges

Add the missing sanity check on the bridge counter to avoid corrupting
data beyond the fixed-sized bridge array in case there are ever more
than eight bridges.

Fixes: a3376e3e ("drm/msm: convert to drm_bridge")
Cc: stable@vger.kernel.org	# 3.12
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/502670/
Link: https://lore.kernel.org/r/20220913085320.8577-5-johan+linaro@kernel.org


Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>