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

Or we will get things like this when we remove the implicit path:

drivers/ssb/embedded.c:32: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
drivers/ssb/driver_chipcommon.c:432: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
drivers/ssb/driver_chipcommon_pmu.c:607: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
drivers/ssb/pcihost_wrapper.c:120: error: ‘THIS_MODULE’ undeclared (first use in this function)
drivers/ssb/driver_pcicore.c:721: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
drivers/ssb/driver_gige.c:249: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/ssb/embedded.c b/drivers/ssb/embedded.c
index eec3e26..9ef124f 100644
--- a/drivers/ssb/embedded.c
+++ b/drivers/ssb/embedded.c
@@ -8,6 +8,7 @@
  * Licensed under the GNU/GPL. See COPYING for details.
  */
 
+#include <linux/export.h>
 #include <linux/ssb/ssb.h>
 #include <linux/ssb/ssb_embedded.h>
 #include <linux/ssb/ssb_driver_pci.h>