qcacmn: Update scheduler_msg callback type

This fixes a CFI failure in callback assignment.

Currently, the callbacks in scheduler_msg are void function
pointers. Update them to have a defined type as
scheduler_msg_process_fn_t to catch type mismatch during
compilation.

Other changes to conform to this new type include:
	1. Cast callback to qdf_mc_timer_callback_t when
	   referencing, and back when assigning
	2. Cast wlan_serialization_generic_timer_cb to
	   take fit into scheduler_msg
	3. Cast target_if_vdev_mgr_rsp_timer_cb to fit
	   into scheduler_msg

Change-Id: I052bc54826d377ae92f5bcc80ca08afb6f5e01e3
CRs-fixed: 2719975

scheduler/inc/scheduler_api.h

@@ -55,6 +55,10 @@ typedef enum {
 	SYS_MSG_ID_UMAC_STOP,
 } SYS_MSG_ID;
 
+struct scheduler_msg;
+typedef QDF_STATUS (*scheduler_msg_process_fn_t)(struct scheduler_msg *msg);
+typedef void (*hdd_suspend_callback)(void);
+
 /**
  * struct scheduler_msg: scheduler message structure
  * @type: message type
@@ -82,8 +86,8 @@ struct scheduler_msg {
 	uint16_t reserved;
 	uint32_t bodyval;
 	void *bodyptr;
-	void *callback;
-	void *flush_callback;
+	scheduler_msg_process_fn_t callback;
+	scheduler_msg_process_fn_t flush_callback;
 	qdf_list_node_t node;
 #ifdef WLAN_SCHED_HISTORY_SIZE
 	QDF_MODULE_ID queue_id;
@@ -101,9 +105,6 @@ struct scheduler_msg {
  */
 void sched_history_print(void);
 
-typedef QDF_STATUS (*scheduler_msg_process_fn_t) (struct scheduler_msg  *msg);
-typedef void (*hdd_suspend_callback)(void);
-
 /**
  * scheduler_init() - initialize control path scheduler
  *