p2p: support frequency for GroupJoin/GroupCreation with config

Accept specific frequency for GroupJoin/GroupCreation.

Bug: 64695709
Test: CtsVerifier - WiFi Direct
Test: manual test
      * specify frequency for Group Owner.
      * The group is run at specified frequency.
      * specify frequency for Group Client.
      * only specified frequency is scanned.
Test: Unit test - atest frameworks/opt/net/wifi/tests/wifitests

Change-Id: I3f4d474379828aacacbdac3a4d4559cfadbac5f6
1 file changed