drm/i915: Remove duplicate inclusion of drm/drm_edid.h

drm/drm_edid.h was included twice.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>