The current drain lantency computation relies on hardcoded limits to
determine when the to use the low vs. high precision multiplier.
Rewrite the code to use a more straightforward approach.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>