BLE privacy timer

Adds another timer with one-shot characteristic that
allows for variable firing of alarms.  Change the BLE
privacy code to use this timer rather than the
BTU continuous timer.

Change-Id: I6baa4e6a76813285c15f24aeb3c7ef942ed01858
diff --git a/include/gki_target.h b/include/gki_target.h
index 8947d5e..673f60b 100644
--- a/include/gki_target.h
+++ b/include/gki_target.h
@@ -82,7 +82,7 @@
 
 /* The number of GKI timers in the software system. */
 #ifndef GKI_NUM_TIMERS
-#define GKI_NUM_TIMERS              3
+#define GKI_NUM_TIMERS              4
 #endif
 
 /* A conversion value for translating ticks to calculate GKI timer.  */