drm/msm/dpu: remove extra clk_round_rate() call

The dev_pm_opp_set_rate() already contains a call for clk_round_rate for
the passed value. Stop calling it manually from
_dpu_core_perf_get_core_clk_rate(). It is slightly incorrect to call it
this way, as we should round the final calculated clock rate rather than
rounding all the intermediate values.
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/550212/
Link: https://lore.kernel.org/r/20230730010102.350713-9-dmitry.baryshkov@linaro.org

drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c

@@ -294,8 +294,6 @@ static u64 _dpu_core_perf_get_core_clk_rate(struct dpu_kms *kms)
 			dpu_cstate = to_dpu_crtc_state(crtc->state);
 			clk_rate = max(dpu_cstate->new_perf.core_clk_rate,
 							clk_rate);
-			clk_rate = clk_round_rate(kms->perf.core_clk,
-					clk_rate);
 		}
 	}