qcacld-3.0: Properly export ol_txrx_flow_control_cb()

We want to enable the compiler's -Wmissing-prototypes switch, but
there is existing code which is generating warnings because not all
public APIs have prototypes defined. Define the missing prototype for
ol_txrx_flow_control_cb().

Change-Id: Ifb7fff891b237e6202cc96afd3ab2e21bc4f13aa
CRs-Fixed: 1104126

core/dp/txrx/ol_tx_send.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2016 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2011-2017 The Linux Foundation. All rights reserved.
  *
  * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
  *
@@ -117,13 +117,6 @@ ol_tx_target_credit_incr_int(struct ol_txrx_pdev_t *pdev, int delta)
 #endif
 
 #if defined(QCA_LL_LEGACY_TX_FLOW_CONTROL)
-/**
- * ol_txrx_flow_control_cb() - call osif flow control callback
- * @vdev: vdev handle
- * @tx_resume: tx resume flag
- *
- * Return: none
- */
 void ol_txrx_flow_control_cb(void *pvdev, bool tx_resume)
 {
 	struct ol_txrx_vdev_t *vdev = pvdev;

core/dp/txrx/ol_tx_send.h

@@ -150,5 +150,13 @@ ol_tx_delay_hist(void *ppdev,
 		 uint16_t *report_bin_values, int category);
 #endif /* QCA_COMPUTE_TX_DELAY */
 
+/**
+ * ol_txrx_flow_control_cb() - call osif flow control callback
+ * @vdev: vdev handle
+ * @tx_resume: tx resume flag
+ *
+ * Return: none
+ */
+void ol_txrx_flow_control_cb(void *vdev, bool tx_resume);
 
 #endif /* _OL_TX_SEND__H_ */