drm/msm/dpu: fix UV scanlines calculation for YUV UBWC formats

drm/msm/dpu: fix UV scanlines calculation for YUV UBWC formats

The UV scanlines is calculated with (height + 1) / 2 unlike
the Y scanlines, add back the correct scanlines calculation
for UBWC YUV formats.

Fixes: 2f3ff6ab8f5c ("drm/msm/dpu: use standard functions in _dpu_format_populate_plane_sizes_ubwc()")
Fixes: ada4a19ed21c ("drm/msm/dpu: rewrite _dpu_format_populate_plane_sizes_ubwc()")
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/718309/
Link: https://lore.kernel.org/r/20260414-topic-sm8x50-msm-dpu1-formats-qc10c-v1-1-0b62325b9030@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>