Add missing USE_PEER_TO_PEER macro definition

include/hcc_detail/hip_hcc.h

@@ -38,6 +38,7 @@ THE SOFTWARE.
 // Compile peer-to-peer support.
 // >= 2 : use HCC hc:accelerator::get_is_peer
 // >= 3 : use hc::am_memtracker_update_peers(...)
+#define USE_PEER_TO_PEER 0
 
 // Use new lock API in HCC:
 #define USE_HCC_LOCK 0