drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.

Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broken
soon.

[ with input from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drivers/base/hypervisor.c

@@ -10,6 +10,7 @@
 
 #include <linux/kobject.h>
 #include <linux/device.h>
+#include <linux/export.h>
 #include "base.h"
 
 struct kobject *hypervisor_kobj;