qcacld-3.0: Remove hdd_unregister_hostapd() prototype

Previously change Ib22dfa375217a48448c5a7872a9a2ed154dd862f
("qcacld-3.0: Refactor & fix the SAP HDD APIs to maintain symmetry")
removed the implementation of hdd_unregister_hostapd() but it failed
to remove the prototype, so remove it now.

Change-Id: I5ee4bebc85395833e667b182e6a2858f0814d883
CRs-Fixed: 2363215

core/hdd/src/wlan_hdd_hostapd.h

@@ -43,8 +43,6 @@ struct hdd_adapter *hdd_wlan_create_ap_dev(struct hdd_context *hdd_ctx,
 				      unsigned char name_assign_type,
 				      uint8_t *name);
 
-QDF_STATUS hdd_unregister_hostapd(struct hdd_adapter *adapter, bool rtnl_held);
-
 eCsrAuthType
 hdd_translate_rsn_to_csr_auth_type(uint8_t auth_suite[4]);