qcacld-3.0: change mode to p2p device for p2p interface

Currently, mode of p2p virtual interface with type managed
is added as sta mode. This may cause issue during p2p find
as in function p2p_vdev_check_valid probe response frames
are dropped for sta mode.

Fix is to convert mode to P2P DEVICE mode from STA mode in
case added interface string contains p2p substring.

Change-Id: I9bf9d8c44af940b42c38cd7819bcdb9c00a90a26
CRs-Fixed: 3036500