nb/intel/haswell: Add native raminit scaffolding

Implement some scaffolding for Haswell native raminit, like bootmode
selection, handling of MRC cache and CPU detection.

Change-Id: Icd96649fa045ea7f0f32ae9bfe1e60498d93975b
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64182
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/northbridge/intel/haswell/native_raminit/Makefile.inc b/src/northbridge/intel/haswell/native_raminit/Makefile.inc
index 8cfb4fb..90af951 100644
--- a/src/northbridge/intel/haswell/native_raminit/Makefile.inc
+++ b/src/northbridge/intel/haswell/native_raminit/Makefile.inc
@@ -1,3 +1,4 @@
 ## SPDX-License-Identifier: GPL-2.0-or-later
 
+romstage-y += raminit_main.c
 romstage-y += raminit_native.c