qcacld-2.0: Add macro for peer_detach

Compile would be blocked for peer_detach if the macro is
not defined. Add macro judge for peer_detach

Change-Id: I206670bf5afb15ed3095351d4a196165b56fbcf0
diff --git a/CORE/SERVICES/WMA/wma.c b/CORE/SERVICES/WMA/wma.c
index c2a82e0..7cccc85 100644
--- a/CORE/SERVICES/WMA/wma.c
+++ b/CORE/SERVICES/WMA/wma.c
@@ -1761,7 +1761,9 @@
 
 	wmi_unified_peer_delete_send(wma->wmi_handle, peer_addr, vdev_id);
 
+#ifdef WLAN_FEATURE_ROAM_OFFLOAD
 peer_detach:
+#endif
 	if (peer)
 		ol_txrx_peer_detach(peer);
 	wma->interfaces[vdev_id].peer_count--;