Fix AMD Agesa leaking Kconfig

Kconfig leaked XIP_ROM_SIZE to other platforms and also
defined obsolete option XIP_ROM_BASE.

Alias AMD_AGESA as NORTHBRIDGE_AMD_AGESA.
Break the circular dependency with family15 Kconfig.

Change-Id: Ic7891012220e1bef758a5a39002b66971d5206e3
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/773
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/northbridge/amd/agesa/Kconfig b/src/northbridge/amd/agesa/Kconfig
index 2ed9fd5..8c0e7ab 100644
--- a/src/northbridge/amd/agesa/Kconfig
+++ b/src/northbridge/amd/agesa/Kconfig
@@ -17,6 +17,12 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 #
 
+config NORTHBRIDGE_AMD_AGESA
+        bool
+        default AMD_AGESA
+
+if NORTHBRIDGE_AMD_AGESA
+
 config CONSOLE_VGA_MULTI
 	bool
 	default n
@@ -26,3 +32,4 @@
 source src/northbridge/amd/agesa/family14/Kconfig
 source src/northbridge/amd/agesa/family15/Kconfig
 
+endif # NORTHBRIDGE_AMD_AGESA