allow to access fastrpc dma buffer trace point

Bug: 170189835
Test: boot
Signed-off-by: Martin Liu <liumartin@google.com>
Change-Id: I674ce9bc8161795ea61da02cb854526b39c2a46c
diff --git a/atrace/genfs_contexts b/atrace/genfs_contexts
new file mode 100644
index 0000000..ce4e879
--- /dev/null
+++ b/atrace/genfs_contexts
@@ -0,0 +1 @@
+genfscon debugfs /tracing/events/fastrpc/fastrpc_dma_stat        u:object_r:debugfs_tracing:s0