Replaced ever growing switch for gen version with chained conditionals.
Futre gen's only need to add a new one if they require something different.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NRobert Beckett <robert.beckett@intel.com>
[danvet: Picked from internal tree and white-wash commit message.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>