soc/intel/baytrail: Add native refcode replacement

- This is a reverse engineered re-implementation of refcode.elf on
	Bay Trail
- Tested on GBYT4, should work everywhere as it's meant to behave
	exactly the same as the binary refcode

Signed-off-by: Mate Kukri <kukri.mate@gmail.com>
Change-Id: I91977c509022b0078804dc151d27296260e24bc4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43133
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/baytrail/Makefile.inc

@@ -49,7 +49,12 @@ ramstage-y += smm.c
 ramstage-y += southcluster.c
 ramstage-y += xhci.c
 ramstage-$(CONFIG_ELOG) += elog.c
-ramstage-$(CONFIG_HAVE_REFCODE_BLOB) += refcode.c
+
+ifeq ($(CONFIG_HAVE_REFCODE_BLOB),y)
+ramstage-y += refcode.c
+else
+ramstage-y += modphy_table.c refcode_native.c
+endif
 
 smm-y += iosf.c
 smm-y += pmutil.c