ueventd: Fix creation of VFIO dev nodes

VFIO nodes, both the container (`vfio`) node and group (numbered)
nodes, should be located in `/dev/vfio`. This change prevents
ueventd from flattening that structure.

Test: Bind a device to VFIO driver to create a VFIO group
Change-Id: I635e9febe6bb52718df263e735479f361eacad4c
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index 0b7ffb8..60dcc2a 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -23,6 +23,11 @@
 subsystem dma_heap
    devname uevent_devpath
    dirname /dev/dma_heap
+
+subsystem vfio
+    devname uevent_devpath
+    dirname /dev/vfio
+
 # ueventd can only set permissions on device nodes and their associated
 # sysfs attributes, not on arbitrary paths.
 #
@@ -43,6 +48,7 @@
 /dev/binder               0666   root       root
 /dev/hwbinder             0666   root       root
 /dev/vndbinder            0666   root       root
+/dev/vfio/*               0666   root       root
 
 /dev/pmsg0                0222   root       log
 /dev/dma_heap/system      0444   system     system