tests: P2P extended listen timing operations

tests: P2P extended listen timing operations

This verifies P2P extended listen timing operations by confirming that a
peer is not discoverable during the provisioning step and that the peer
becomes discoverable after having removed the group during such
provisioning step. The latter case was broken until the 'P2P: Cancel
group formation when deleting a group during group formation' commit.

Signed-off-by: Jouni Malinen <j@w1.fi>