Doxygen and some build tools may get a bit confused about same file
name being used in different directories. Clean this up a bit by
renaming some of the duplicated file names in src/ap.
This code can be shared by both hostapd and wpa_supplicant and this
is an initial step in getting the generic code moved to be under the
src directories. Couple of generic files still remain under the
hostapd directory due to direct dependencies to files there. Once the
dependencies have been removed, they will also be moved to the src/ap
directory to allow wpa_supplicant to be built without requiring anything
from the hostapd directory.
config.c includes now only the generic helper functions that are needed
both for hostapd and the AP mode operations in wpa_supplicant.
hostapd/config_file.c is only needed for hostapd.
