Set PCL command should be sent to firmware only for STA mode.
For P2P vdev, except the connected band, the other band channels
are marked disallowed. With this, if the set PCL command is sent
then STA can't roam to the disallowed channels.
Hence don't send PCL command if the vdev opmode is not Station.
Change-Id: I6c4917f75d5f14169e2c564d5f6deee819fb629a
CRs-Fixed: 2939148