drm/fb-helper: Redundant info->fix.type_aux setting in drm_fb_helper_fill_fix()

The variable info->fix.type_aux is set to zero twice in the function
drm_fb_helper_fill_fix().  This patch removes one redundant.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>