Some members in struct mixer_context aren't used and the define
HDMI_OVERLAY_NUMBER is unused in hdmi driver, remove them.
Signed-off-by: NJoonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NInki Dae <inki.dae@samsung.com>