qcacmn: Add WAR for dp_soc_attach_wifi3 -Wmissing-prototypes

Currently dp_main.c generates warnings when compiled with the GCC
-Wmissing-prototypes switch because it does not include a header file
which exports a prototype for dp_soc_attach_wifi3(). Currently the "dp
soc attach" APIs are defined in a strange manner, and there is not a
prototype which dp_main.c can include. So as a WAR define the
prototype internal to dp_main.c itself.

Of course the whole point of -Wmissing-prototypes is to prevent
mismatches between callers of an interface and the implementation of
an interface, and this WAR explicitly bypasses that protection. This
WAR should be superceded in the future by a proper registration
mechanism where the architecture-specific DP implementation attaches
to the Converged Data Path (CDP).

Change-Id: I1858ac4ec9f53c28cde622a43a3adb8643328916
CRs-Fixed: 1110197

dp/wifi3.0/dp_main.c

@@ -1795,6 +1795,14 @@ static struct cdp_ops dp_txrx_ops = {
  *
  * Return: DP SOC handle on success, NULL on failure
  */
+/*
+ * Local prototype added to temporarily address warning caused by
+ * -Wmissing-prototypes. A more correct solution, namely to expose
+ * a prototype in an appropriate header file, will come later.
+ */
+void *dp_soc_attach_wifi3(void *osif_soc, void *hif_handle,
+	HTC_HANDLE htc_handle, qdf_device_t qdf_osdev,
+	struct ol_if_ops *ol_ops);
 void *dp_soc_attach_wifi3(void *osif_soc, void *hif_handle,
 	HTC_HANDLE htc_handle, qdf_device_t qdf_osdev,
 	struct ol_if_ops *ol_ops)