Maintain base page handling functions in order of
alloc, free, init. No functional changes.

v2: s/Introduce/Maintain (Michel)
v3: Rebase

Cc: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>