drm/msm/dpu: sync mode_config limits to the FB limits in dpu_plane.c

drm/msm/dpu: sync mode_config limits to the FB limits in dpu_plane.c

Lift mode_config limits set by the DPU driver to the actual FB limits as
handled by the dpu_plane.c. Move 2*max_lm_width check where it belongs,
to the drm_crtc_helper_funcs::mode_valid() callback.

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/612259/
Link: https://lore.kernel.org/r/20240903-dpu-mode-config-width-v6-15-617e1ecc4b7a@linaro.org