drm/msm/dpu: increase memtype count to 16 for sm8550

sm8550 has 16 vbif clients.

This fixes the extra 2 clients (DMA4/DMA5) not having their memtype
initialized. This fixes DMA4/DMA5 planes not displaying correctly.

Fixes: efcd0107 ("drm/msm/dpu: add support for SM8550")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Patchwork: https://patchwork.freedesktop.org/patch/550968/
Link: https://lore.kernel.org/r/20230802134900.30435-1-jonathan@marek.ca


[DB: fixed the Fixes tag]
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>