infiniband: Fix up users implicitly relying on getting stat.h

They get it via module.h (via device.h) but we want to clean that up.
When we do, we'll get things like:

CC [M] drivers/infiniband/core/sysfs.o
sysfs.c:361: error: 'S_IRUGO' undeclared here (not in a function)
sysfs.c:654: error: 'S_IWUSR' undeclared here (not in a function)

so add in the stat header it is using explicitly in advance.

Signed-off-by: Paul Gortmaker <[e-mail]>

drivers/infiniband/core/sysfs.c

···
 #include "core_priv.h"
 
 #include <linux/slab.h>
+#include <linux/stat.h>
 #include <linux/string.h>
 
 #include <rdma/ib_mad.h>

drivers/infiniband/hw/ipath/ipath_init_chip.c

···
 #include <linux/pci.h>
 #include <linux/netdevice.h>
 #include <linux/slab.h>
+#include <linux/stat.h>
 #include <linux/vmalloc.h>
 
 #include "ipath_kernel.h"

drivers/infiniband/hw/ipath/ipath_sysfs.c

···
  */
 
 #include <linux/ctype.h>
+#include <linux/stat.h>
 
 #include "ipath_kernel.h"
 #include "ipath_verbs.h"

drivers/infiniband/hw/mthca/mthca_provider.c

···
 
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/stat.h>
 #include <linux/mm.h>
 
 #include "mthca_dev.h"