drm/msm/dp: Inline dp_link_parse_sink_count()

drm/msm/dp: Inline dp_link_parse_sink_count()

The function dp_link_parse_sink_count() is really just
drm_dp_read_sink_count(). It debug prints out the bit for content
protection (DP_SINK_CP_READY), but that is not useful beyond debug
because 'link->dp_link.sink_count' is overwritten to only contain the
sink_count in this same function. Just use drm_dp_read_sink_count() in
the one place this function is called to simplify.

Cc: Vinod Polimera <quic_vpolimer@quicinc.com>
Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.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/554987/
Link: https://lore.kernel.org/r/20230829184735.2841739-7-swboyd@chromium.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>