DPP: Fix number of Authentication Request retry cases

DPP: Fix number of Authentication Request retry cases

Previous implementation did not handle number of sequences correctly.
Make sure the iteration continues in both unicast and broadcast cases
until the five attempts have been made. In addition, improve timing by
checking 10 second time from the beginning of each iteration round and
not the last channel on which the Auth Req frame has been transmitted.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>