blackfin: Add export.h to files using EXPORT_SYMBOL/THIS_MODULE

These particular files were just assuming that module.h was
somehow in the include paths.  Give them the more minimalist
header file explicitly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/blackfin/mach-bf537/boards/stamp.c b/arch/blackfin/mach-bf537/boards/stamp.c
index 6c916a6..27f955d 100644
--- a/arch/blackfin/mach-bf537/boards/stamp.c
+++ b/arch/blackfin/mach-bf537/boards/stamp.c
@@ -1992,6 +1992,7 @@
 
 #if defined(CONFIG_BACKLIGHT_ADP8860) || defined(CONFIG_BACKLIGHT_ADP8860_MODULE)
 #include <linux/i2c/adp8860.h>
+#include <linux/export.h>
 static struct led_info adp8860_leds[] = {
 	{
 		.name = "adp8860-led7",