drm/mcde: Fix compile problems

Some further compile problems appeared while merging the
patch, fix them up.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190526113624.6702-1-linus.walleij@linaro.org