qcacld-3.0: Remove struct set_context_req

The last use of struct set_context_req was removed by:
  qcacld-3.0: Remove lim_is_sme_set_context_req_valid()
  Change-Id Ib60ae088401faa503db7201456c1c0ba1ab4917b

Since this struct is now obsolete, remove it.

Change-Id: I377dad835e5d1184f8c89441ccd804122f51ce9d
CRs-Fixed: 3431490

core/mac/inc/sir_api.h

@@ -1307,17 +1307,6 @@ struct missed_beacon_ind {
 	int32_t rssi;
 };
 
-/* / Definition for Set Context request */
-/* / ---> MAC */
-struct set_context_req {
-	uint16_t messageType;   /* eWNI_SME_SET_CONTEXT_REQ */
-	uint16_t length;
-	uint8_t vdev_id;      /* vdev ID */
-	struct qdf_mac_addr peer_macaddr;
-	struct qdf_mac_addr bssid;      /* BSSID */
-	tSirKeyMaterial keyMaterial;
-};
-
 /* / Definition for Set Context response */
 /* / MAC ---> */
 struct set_context_rsp {