Fix a run-time integer overflow

Change-Id: I87255d8a25ef8c7d235cbf3c8887d7bed7892cfe

vp9/vp9_cx_iface.c

diff --git a/vp9/vp9_cx_iface.c b/vp9/vp9_cx_iface.c
index 1c6413d..8a97486 100644
--- a/vp9/vp9_cx_iface.c
+++ b/vp9/vp9_cx_iface.c
@@ -805,7 +805,7 @@
 }
 
 // vp9 uses 10,000,000 ticks/second as time stamp
-#define TICKS_PER_SEC 10000000
+#define TICKS_PER_SEC 10000000LL
 
 static int64_t timebase_units_to_ticks(const vpx_rational_t *timebase,
                                        int64_t n) {