drm: Move all decl for drm_edid.c to drm_edid.h

Some were still left in drm_crtc.h. Also include drm_edid.h in the
rst files.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160831160913.12991-4-daniel.vetter@ffwll.ch
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 48fc5a9..bb4254d 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -208,6 +208,9 @@
 EDID Helper Functions Reference
 ===============================
 
+.. kernel-doc:: include/drm/drm_edid.h
+   :internal:
+
 .. kernel-doc:: drivers/gpu/drm/drm_edid.c
    :export: