Makefile.inc: Move adding bootblock on non-x86 targets

This can be done in a separate Makefile target.

Change-Id: I50eae4f00d171d26a221ca969086f4f294fa524b
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63217
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

Makefile.inc

@@ -1116,10 +1116,6 @@ ifeq ($(CONFIG_ARCH_X86),y)
 		-b -$(call file-size,$(objcbfs)/bootblock.bin) $(cbfs-autogen-attributes) \
 		$(TS_OPTIONS) \
 		$(CBFSTOOL_ADD_CMD_OPTIONS)
-else # ifeq ($(CONFIG_ARCH_X86),y)
-	$(CBFSTOOL) $@.tmp write -u \
-		-r BOOTBLOCK \
-		-f $(objcbfs)/bootblock.bin
 endif # ifeq ($(CONFIG_ARCH_X86),y)
 	$(prebuild-files) true
 	mv $@.tmp $@
@@ -1150,6 +1146,12 @@ add_intermediate = \
 	$(1): $(obj)/coreboot.pre $(2) | $(INTERMEDIATE) \
 	$(eval INTERMEDIATE+=$(1)) $(eval PHONY+=$(1))
 
+ifneq ($(CONFIG_ARCH_X86),y)
+$(call add_intermediate, add_bootblock, $(objcbfs)/bootblock.bin)
+	printf "    FMAP       writing BOOTBLOCK region\n"
+	$(CBFSTOOL) $< write -u -r BOOTBLOCK -f $(objcbfs)/bootblock.bin
+endif
+
 $(obj)/coreboot.rom: $(obj)/coreboot.pre $(CBFSTOOL) $(IFITTOOL) $$(INTERMEDIATE)
 	@printf "    CBFS       $(subst $(obj)/,,$(@))\n"
 # The full ROM may be larger than the CBFS part, so create an empty