... instead of calling each one for each generation indiviudally.

Notice that we've already managed to be inconsistent, the resume path
is missing an IS_VLV check. As a nice benefit we can mark all the
platform specific enable/disable functions as static and hide them in
intel_pm.c
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>