drm/core: Fix ordering in drm_mode_config_cleanup.

__drm_atomic_helper_plane_destroy_state calls
drm_framebuffer_unreference, which means that if drm_framebuffer_free
is called before plane->destroy freed memory will be accessed.

A similar case happens for the blob list, which was freed before the
crtc state was, resulting in the unreference_blob from crtc_destroy_state
pointing to garbage memory causing another opportunity for a GPF.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458657734-21866-1-git-send-email-maarten.lankhorst@linux.intel.com