qcacld-3.0: Remove wma_register_roam_vdev_disc_event_handler()
A prototype for wma_register_roam_vdev_disc_event_handler() was added
by:
qcacld-3.0: Process Disconnect request from FW
Change-Id Ic1e83aace48a3e8424f23641b0e77c66f4283587
However, no actual function was added, so remove the prototype.
Change-Id: I4c6f41f93bb80f733031f4a77a94ee0b4cad6f1c
CRs-Fixed: 3434499