drm/msm/mdp4: move HW revision detection to earlier phase

Fixes if condition, which never worked inside mdp4_kms_init, since
HW detection has been done later in mdp4_hw_init.

Fixes: eb2b47bb ("drm/msm/mdp4: only use lut_clk on mdp4.2+")

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20210705231641.315804-2-david@ixit.cz


Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>