This commit merges the driver_ops structures and implementations from
hostapd/driver*.[ch] into src/drivers. This is only an initial step and
there is room for number of cleanups to share code between the hostapd
and wpa_supplicant parts of the wrappers to avoid unnecessary source
code duplication.
wpa_supplicant can now initialize hostapd data structures when mode=2 is
used to set up an AP. The hostapd configuration is not yet set based on
wpa_supplicant network configuration block. In addition, the glue code
for hostapd driver_ops needs number of functions that will be needed for
AP functionality.
