rmodules: use rmodtool to create rmodules

Start using the rmodtool for generating rmodules.
rmodule_link() has been changed to create 2 rules:
one for the passed in <name>, the other for creating
<name>.rmod which is an ELF file in the format of
an rmodule.

Since the header is not compiled and linked together
with an rmodule there needs to be a way of marking
which symbol is the entry point. __rmodule_entry is
the symbol used for knowing the entry point. There
was a little churn in SMM modules to ensure an
rmodule entry point symbol takes a single argument.

Change-Id: Ie452ed866f6596bf13f137f5b832faa39f48d26e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/5379
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)

src/cpu/x86/smm/Makefile.inc

@@ -21,10 +21,8 @@ ramstage-$(CONFIG_BACKUP_DEFAULT_SMM_REGION) += backup_default_smm.c
 
 ifeq ($(CONFIG_SMM_MODULES),y)
 smmstub-y += smm_stub.S
-smmstub-y += smm_module_header.c
 
 smm-y += smiutil.c
-smm-y += smm_module_header.c
 smm-y += smm_module_handler.c
 
 ramstage-y += smm_module_loader.c
@@ -40,7 +38,7 @@ $(obj)/cpu/x86/smm/smmstub.o: $$(smmstub-objs)
 # Link the SMM stub module with a 0-byte heap.
 $(eval $(call rmodule_link,$(obj)/cpu/x86/smm/smmstub.elf, $(obj)/cpu/x86/smm/smmstub.o, 0))
 
-$(obj)/cpu/x86/smm/smmstub: $(obj)/cpu/x86/smm/smmstub.elf
+$(obj)/cpu/x86/smm/smmstub: $(obj)/cpu/x86/smm/smmstub.elf.rmod
 	$(OBJCOPY) -O binary $< $@
 
 $(obj)/cpu/x86/smm/smmstub.ramstage.o: $(obj)/cpu/x86/smm/smmstub
@@ -55,7 +53,7 @@ $(obj)/cpu/x86/smm/smm.o: $$(smm-objs) $(LIBGCC_FILE_NAME)
 
 $(eval $(call rmodule_link,$(obj)/cpu/x86/smm/smm.elf, $(obj)/cpu/x86/smm/smm.o, $(CONFIG_SMM_MODULE_HEAP_SIZE)))
 
-$(obj)/cpu/x86/smm/smm: $(obj)/cpu/x86/smm/smm.elf
+$(obj)/cpu/x86/smm/smm: $(obj)/cpu/x86/smm/smm.elf.rmod
 	$(OBJCOPY) -O binary $< $@
 
 $(obj)/cpu/x86/smm/smm.ramstage.o: $(obj)/cpu/x86/smm/smm