nb/intel/haswell: Move MRC glue code into a subfolder

Put the Haswell MRC glue code inside a `haswell_mrc` subfolder. Future
commits will move the Broadwell MRC/refcode glue code to be in Haswell
northbridge scope, so plan in advance.

Tested on Asrock B85M Pro4, still boots.

Change-Id: Id3e26ec1c2d5ccce928083d7ce41445908df8cf3
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55523
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/haswell/Makefile.inc b/src/northbridge/intel/haswell/Makefile.inc
index f718f9a..2d1532b 100644
--- a/src/northbridge/intel/haswell/Makefile.inc
+++ b/src/northbridge/intel/haswell/Makefile.inc
@@ -13,17 +13,12 @@
 ramstage-y += minihd.c
 
 romstage-y += memmap.c
-romstage-y += raminit.c
 romstage-y += romstage.c
 romstage-y += early_init.c
 romstage-y += report_platform.c
 
-# We don't ship that, but booting without it is bound to fail
-cbfs-files-$(CONFIG_HAVE_MRC) += mrc.bin
-mrc.bin-file := $(call strip_quotes,$(CONFIG_MRC_FILE))
-mrc.bin-position := 0xfffa0000
-mrc.bin-type := mrc
-
 postcar-y += memmap.c
 
+subdirs-y += haswell_mrc
+
 endif