sparc: add export.h to arch/sparc files as required

These files are only exporting symbols, so they don't need
the full module.h header file.  Previously they were getting
access to EXPORT_SYMBOL implicitly via overuse of module.h
from within other .h files, but that is being cleaned up.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/sparc/kernel/vio.c b/arch/sparc/kernel/vio.c
index 3cb1def..f67e28e 100644
--- a/arch/sparc/kernel/vio.c
+++ b/arch/sparc/kernel/vio.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/irq.h>
+#include <linux/export.h>
 #include <linux/init.h>
 
 #include <asm/mdesc.h>