qcacmn: Cleanup CONFIG_MCL from qdf nbuff replenish apis

In the current implementation, qdf nbuff replenish timer apis
invocation is controlled by macro CONFIG_MCL. So replace the
CONFIG_MCL with new flag FEATURE_NBUFF_REPLENISH_TIMER.

Change-Id: I8231483b791edf25c08ec4a794b5cc7b638daec7
CRs-Fixed: 2421538

qdf/linux/src/qdf_nbuf.c

@@ -226,7 +226,7 @@ void qdf_nbuf_set_state(qdf_nbuf_t nbuf, uint8_t current_state)
 }
 qdf_export_symbol(qdf_nbuf_set_state);
 
-#ifdef CONFIG_MCL
+#ifdef FEATURE_NBUFF_REPLENISH_TIMER
 /**
  * __qdf_nbuf_start_replenish_timer - Start alloc fail replenish timer
  *