aom_ports: Silence warnings in aom_timer.h

When CONFIG_OS_SUPPORT is not enabled the aom_timer timer function
stubs cause unused parameter warnings. This comments out the arg
names and silences the warning.

Change-Id: I97bdbcbebdf081ac5cb2ffd86439028a1e672fa2

aom_ports/aom_timer.h

diff --git a/aom_ports/aom_timer.h b/aom_ports/aom_timer.h
index cc5203c..d684c3a 100644
--- a/aom_ports/aom_timer.h
+++ b/aom_ports/aom_timer.h
@@ -97,11 +97,13 @@
   void *dummy;
 };
 
-static INLINE void aom_usec_timer_start(struct aom_usec_timer *t) {}
+static INLINE void aom_usec_timer_start(struct aom_usec_timer * /*t*/) {}
 
-static INLINE void aom_usec_timer_mark(struct aom_usec_timer *t) {}
+static INLINE void aom_usec_timer_mark(struct aom_usec_timer * /*t*/) {}
 
-static INLINE int aom_usec_timer_elapsed(struct aom_usec_timer *t) { return 0; }
+static INLINE int aom_usec_timer_elapsed(struct aom_usec_timer * /*t*/) {
+  return 0;
+}
 
 #endif /* CONFIG_OS_SUPPORT */