Mode limitation checked in mixer driver affects only older HW.
Mixer in Exynos542x has no such limitations. While at it patch changes
validation callback to recently introduced mode_valid which is more
suitable for the check. Additionally little cleanup is performed.
Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Reviewed-by: NTobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: NInki Dae <inki.dae@samsung.com>