drm_get_edid will store edid into raw_edid, so when freeing edid memory,
at the same time clean raw_edid pointer.
Signed-off-by: NMa Ling <ling.ma@intel.com>
[anholt: Note that raw_edid is not currently used anywhere]
Signed-off-by: NEric Anholt <eric@anholt.net>