drm/msm/dpu: drop INTF_TYPE_MAX symbol

This enum value does not correspond to any of actual interface types,
it's not used by the driver, and the value of INTF_WB is greater than
INTF_TYPE_MAX. Thus this symbol serves no purpose and can be removed.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/475556/
Link: https://lore.kernel.org/r/20220222062246.242577-3-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>