P2P: Fix channel preference use for MCC p2p_connect
Only force_freq was used in the wpas_p2p_set_own_freq_preference() call
which allowed the P2P module channel re-selection to ignore the
preference for using a channel we are already using. Fix this by setting
either force_freq or pref_freq as the preference based on which one is
set. This allows p2p_ignore_shared_freq parameter to be used whether to
prefer the shared frequency in this case.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>