Declare recovery and developer modes outside ChromeOS

Move the implementation for recovery and developer modes from
vendorcode/google/chromes to lib/.

Change-Id: I33335fb282de2c7bc613dc58d6912c47f3b5c06c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/4308
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/lib/Makefile.inc

@@ -128,6 +128,9 @@ smm-y += gcc.c
 
 $(obj)/lib/version.ramstage.o : $(obj)/build.h
 
+romstage-y += bootmode.c
+ramstage-y += bootmode.c
+
 ifeq ($(CONFIG_RELOCATABLE_MODULES),y)
 ramstage-y += rmodule.c
 romstage-$(CONFIG_RELOCATABLE_RAMSTAGE) += rmodule.c