drm/msm/dsi: update hdisplay calculation for dsi_timing_setup

Currently, hdisplay is being divided by 3 for DSC. However, this
calculation only works for cases where BPP = 8.

Update hdisplay calculation to be bytes_per_line / 3, so that it
accounts for cases where BPP != 8.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/539271/
Link: https://lore.kernel.org/r/20230329-rfc-msm-dsc-helper-v14-9-bafc7be95691@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -949,7 +949,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
 		 * pulse width same
 		 */
 		h_total -= hdisplay;
-		hdisplay /= 3;
+		hdisplay = msm_dsc_get_bytes_per_line(msm_host->dsc) / 3;
 		h_total += hdisplay;
 		ha_end = ha_start + hdisplay;
 	}