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>

Author: akhilpo-qcom

drivers/gpu/drm/msm/adreno/a6xx_gmu.c

@@ -1731,6 +1731,7 @@ static int a6xx_gmu_acd_probe(struct a6xx_gmu *gmu)
 		u32 val;
 
 		freq = gmu->gpu_freqs[i];
+		/* This is unlikely to fail because we are passing back a known freq */
 		opp = dev_pm_opp_find_freq_exact(&gpu->pdev->dev, freq, true);
 		np = dev_pm_opp_get_of_node(opp);