drm: sti: Add DRM driver itself

Make the link between all the hardware drivers and DRM/KMS interface.
Create the driver itself and make it register all the sub-components.
Use GEM CMA helpers for buffer allocation.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>

diff --cc drivers/gpu/drm/sti/Kconfig
Simple merge

diff --cc drivers/gpu/drm/sti/Makefile
Simple merge

diff --cc drivers/gpu/drm/sti/sti_compositor.c
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_crtc.c
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_crtc.h
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_drv.c
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_drv.h
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_plane.c
Simple merge

diff --cc drivers/gpu/drm/sti/sti_drm_plane.h
Simple merge