drm/msm/a6xx: Add a comment to acd_probe()

It is not obvious why we can skip error checking of
dev_pm_opp_find_freq_exact() API. Add a comment explaining it.

Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/672263/
Link: https://lore.kernel.org/r/20250902-assorted-sept-1-v1-4-f3ec9baed513@oss.qualcomm.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>