drm: Extract drm_framebuffer.[hc]

Also start with drm_modeset.h with the core bits, since we need
to untangle this mess somehow. That allows us to move the drm_modes.h
include to the right spot, except for the temporary connector status
enum. That will get fixed as soon as drm_connector.h exists.

v2: Rebase.

v3: Move drm_crtc_force_disable_all back again, that wasn't meant to
be moved (Sean).

v4: Rebase.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 48e1a56..fed9fe8 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -27,6 +27,8 @@
 #ifndef __DRM_MODES_H__
 #define __DRM_MODES_H__
 
+#include <drm/drm_modeset.h>
+
 /*
  * Note on terminology:  here, for brevity and convenience, we refer to connector
  * control chips as 'CRTCs'.  They can control any type of connector, VGA, LVDS,