drm: extract drm_atomic_uapi.c

This leaves all the commit/check and state handling in drm_atomic.c,
while pulling all the uapi glue and the huge ioctl itself into a
seprate file.

This seems to almost perfectly split the rather big drm_atomic.c file
into 2 equal sizes.

Also adjust the kerneldoc and type a very terse overview text.

v2: Rebase.

v3: Fix tiny typo.

v4:
- Fixup armada, newly converted atomic driver hooray!
- Fixup msm/dpu1, newly added too.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905135711.28370-7-daniel.vetter@ffwll.ch

include/drm/drm_atomic.h

@@ -584,22 +584,6 @@ __drm_atomic_get_current_plane_state(struct drm_atomic_state *state,
 	return plane->state;
 }
 
-int __must_check
-drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
-			     const struct drm_display_mode *mode);
-int __must_check
-drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
-				  struct drm_property_blob *blob);
-int __must_check
-drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
-			      struct drm_crtc *crtc);
-void drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
-				 struct drm_framebuffer *fb);
-void drm_atomic_set_fence_for_plane(struct drm_plane_state *plane_state,
-				    struct dma_fence *fence);
-int __must_check
-drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
-				  struct drm_crtc *crtc);
 int __must_check
 drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
 				   struct drm_crtc *crtc);