DPP2: Chirping in hostapd Enrollee

DPP2: Chirping in hostapd Enrollee

Add a new hostapd control interface command "DPP_CHIRP own=<BI ID>
iter=<count>" to request chirping, i.e., sending of Presence
Announcement frames, to be started. This follows the model of similar
wpa_supplicant functionality from commit 562f77144cd2 ("DPP2: Chirping
in wpa_supplicant Enrollee"). The hostapd case requires the AP to be
started without beaconing, i.e., with start_disabled=1 in hostapd
configuration, to allow iteration of channels needed for chirping.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>