drm/msm/dsi: Drop dev_pm_opp_set_rate(0)

drm/msm/dsi: Drop dev_pm_opp_set_rate(0)

dev_pm_opp_set_rate(0) removes the vote specified in required-opps but
does not actually park the clock, making it run without the necessary
power backing. Drop the explicit call to it.

Every call site of ops->link_clk_disable() is followed by
pm_runtime_put(), so the power vote will be rescinded if deemed safe.

Fixes: 32d3e0feccfe ("drm/msm: dsi: Use OPP API to set clk/perf state")
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/742783/
Link: https://lore.kernel.org/r/20260728-topic-dpu_power-v1-3-e7783b859a70@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>