drm/sti: drop use of drmP.h

Stop using the deprecated drmP.h header file.
Replaced with relevant forwards or headers files.
Header files sorted in all files touched.

Build tested with allyesconfig, allmodconfig for a number of
architectures.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190605134835.25112-2-sam@ravnborg.org

gpu: drm: sti: Adopt SPDX identifiers

Add SPDX identifiers to files under sti directory

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Vincent Abriou <vincent.abriou@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171206112947.9569-2-benjamin.gaignard@st.com

drm/sti: atomic crtc/plane update

Better fit STI hardware structure.
Planes are no more responsible of updating mixer information such
as z-order and status. It is now up to the CRTC atomic flush to
do it. Plane actions (enable or disable) are performed atomically.
Disabling of a plane is synchronize with the vsync event.

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

drm/sti: code clean up

Purpose is to simplify the STI driver:
- remove layer structure
- consider video subdev as part of the compositor (like mixer subdev)
- remove useless STI_VID0 and STI_VID1 enum

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

drm: sti: add cursor plane

stih407 SoC have a dedicated hardware cursor plane,
this patch enable it.
The hardware have a color look up table, fix it to
be able to use ARGB8888.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>