AMD Family 0Fh: ensure CONFIG_CBB and CONFIG_CDB have sane values

(this probably fixes relocate_sb_ht_chain() on tyan/s2885)

Change-Id: I5a26f4280b00bfb259c600048f6a7391a6c1268f
Signed-off-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
Reviewed-on: http://review.coreboot.org/10913
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/northbridge/amd/amdk8/Kconfig

@@ -119,4 +119,12 @@ config IOMMU
 	bool
 	default y
 
+config CBB
+	hex
+	default 0x00
+
+config CDB
+	hex
+	default 0x18
+
 endif #NORTHBRIDGE_AMD_K8