We have a standard hook for reading out the current cdclk. Move the VLV
code from valleyview_cur_cdclk() to .get_display_clock_speed().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>