pci: Fix files needing export.h for EXPORT_SYMBOL/THIS_MODULE

They were implicitly getting it from device.h --> module.h but
we want to clean that up.  So add the minimal header for these
macros.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 2f10328..0e6d04d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -11,6 +11,7 @@
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
+#include <linux/export.h>
 #include <linux/ioport.h>
 #include <linux/pci.h>
 #include <linux/proc_fs.h>