configs: Add a target to buildtest the ivybridge mrc.bin bootpath

Change-Id: Iff15e9586cd3e39850d986582b5943cbb8a184a7
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32384
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

configs/config.lenovo_x220_mrc_bin

@@ -0,0 +1,3 @@
+CONFIG_VENDOR_LENOVO=y
+CONFIG_BOARD_LENOVO_X220=y
+# CONFIG_USE_NATIVE_RAMINIT is not set