IB/hns: Support compile test for hns RoCE driver

Compiling the hns RoCE driver requires ARM architecture.
In order to simplify development of IB/core, support
compile test. Add the necessary includes for that too.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c
index 605962f..e1b433c 100644
--- a/drivers/infiniband/hw/hns/hns_roce_alloc.c
+++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c
@@ -32,6 +32,7 @@
  */
 
 #include <linux/platform_device.h>
+#include <linux/vmalloc.h>
 #include "hns_roce_device.h"
 
 int hns_roce_bitmap_alloc(struct hns_roce_bitmap *bitmap, unsigned long *obj)