drm: Remove duplicate forward declaration

Forward declarations in C are great but I'm pretty sure one is enough.

Signed-off-by: Dawid Kurek <[e-mail]>
Signed-off-by: Sean Paul <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

include/drm/drm_connector.h

···
 
 #include <uapi/drm/drm_mode.h>
 
-struct drm_device;
-
 struct drm_connector_helper_funcs;
 struct drm_modeset_acquire_ctx;
 struct drm_device;