qcacld-3.0: Send vdev create cmd from vdevmgr_mlme_ext_hdl_create

In current implementation, vdev create command is sent to the FW from
vdevmgr_mlme_ext_post_hdl_create. By design vdev create command should
be sent to the firmware from vdevmgr_mlme_ext_hdl_create.

To align with the design, send vdev create command from
vdevmgr_mlme_ext_hdl_create.

Change-Id: I42203ae5c4f75388e520e7fc3bd9114dd3236492
CRs-Fixed: 2714533