sb/intel/{bd82x6,ibexpeak}: Move RCBA macros to a common location

Many generations of Intel hardware have identical code concerning the
RCBA.

Change-Id: I33ec6801b115c0d64de1d2a0dc5d439186f3580a
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/23287
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/southbridge/intel/bd82x6x/pcie.c b/src/southbridge/intel/bd82x6x/pcie.c
index 34b7694..1f4c157 100644
--- a/src/southbridge/intel/bd82x6x/pcie.c
+++ b/src/southbridge/intel/bd82x6x/pcie.c
@@ -21,6 +21,7 @@
 #include <device/pci_ids.h>
 #include <southbridge/intel/common/pciehp.h>
 #include <assert.h>
+#include <southbridge/intel/common/rcba.h>
 #include "pch.h"
 
 static void pch_pcie_pm_early(struct device *dev)