qcacmn: Fix uninitialized subtype usage by policy manager

Currently, Updation of vdev related parameters
policy_mgr_vdev_entry_info is conditional. Conditional
updation can cause uninitialized usage of subtype of
policy_mgr_vdev_entry_info by policy manager to get concurrency
mode.

Fix is to initialize policy_mgr_vdev_entry_info with zero.

Change-Id: Ib11a5de8ab19c27bdb0f8993bdadc76131d7bbd1
CRs-Fixed: 2489696