kvm: fix implicit use of stat.h header file

This was coming in via an implicit module.h (and its sub-includes)
before, but we'll be cleaning that up shortly.  Call out the stat.h
include requirement in advance.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

virt/kvm/iommu.c

@@ -26,6 +26,7 @@
 #include <linux/list.h>
 #include <linux/kvm_host.h>
 #include <linux/pci.h>
+#include <linux/stat.h>
 #include <linux/dmar.h>
 #include <linux/iommu.h>
 #include <linux/intel-iommu.h>