avr32: add export.h to arch/avr32 for EXPORT_SYMBOL/THIS_MODULE

Add it in where the module.h implicit presence was doing
the job before.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c
index 3c00422..50cdb5b 100644
--- a/arch/avr32/mm/dma-coherent.c
+++ b/arch/avr32/mm/dma-coherent.c
@@ -8,6 +8,7 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/gfp.h>
+#include <linux/export.h>
 
 #include <asm/addrspace.h>
 #include <asm/cacheflush.h>