nb/intel/i945: Switch to POSTCAR_STAGE

Change-Id: Ibbe6aa55a4efe4a2675c757ba2ab2b56055c60ac
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/26785
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
diff --git a/src/northbridge/intel/i945/Makefile.inc b/src/northbridge/intel/i945/Makefile.inc
index 0e4fcfc..ffeabdc 100644
--- a/src/northbridge/intel/i945/Makefile.inc
+++ b/src/northbridge/intel/i945/Makefile.inc
@@ -29,4 +29,6 @@
 
 smm-y += udelay.c
 
+postcar-y += ram_calc.c
+
 endif