vendorcode: 64bit fixes for AMD CIMX SB800

Make SB800 code compile with x64 compiler

These fixes probably apply 1:1 to the other SB components
in that directory.

Change-Id: I9ff9f27dff5074d2faf41ebc14bfe50871d9c7f7
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Signed-off-by: Scott Duplichan <scott@notabs.org>
Reviewed-on: http://review.coreboot.org/10573
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
diff --git a/src/vendorcode/amd/cimx/sb800/SBMAIN.c b/src/vendorcode/amd/cimx/sb800/SBMAIN.c
index eb21770..a494d30 100644
--- a/src/vendorcode/amd/cimx/sb800/SBMAIN.c
+++ b/src/vendorcode/amd/cimx/sb800/SBMAIN.c
@@ -240,7 +240,7 @@
  * @param[in] Data    Callback specific data.
  * @param[in] pConfig Southbridge configuration structure pointer.
  */
-UINTN
+UINT32
 CallBackToOEM (
   IN       UINT32 Func,
   IN       UINT32 Data,