app_osplookup: Move header defines into the app.

astosp.h is leftover from when logic was split between app_osplookup and
res_osp.  All logic was moved into app_osplookup by 109737eb in 2006,
but astosp.h remained.  This moves the remaining defines into
app_osplookup and deletes astosp.h.

Change-Id: I0a6c4debd7c9543b608520b1765abfa4fab7b2fd