Adding chv specific fre/encode conversion.

v2: Remove generic function and platform check (Daniel)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>