common: Add symbol handling for generic lists into Makefile

This patch adds essential components for generation of the contents of
the linker section that is used by the linker-generated array. All of
the contents is held in a separate file, u-boot.lst, which is generated
at runtime just before U-Boot is linked.

The purpose of this code is to especially generate the appropriate
boundary symbols around each subsection in the section carrying the
linker-generated arrays. Obviously, the interim linker code for actual
placement of the variables into the section is generated too. The
generated file, u-boot.lst, is included into u-boot.lds via the linker
INCLUDE directive in u-boot.lds .

Adjustments are made in the Makefile and spl/Makefile so that the
u-boot.lds and u-boot-spl.lds depend on their respective .lst files.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Tested-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/spl/Makefile b/spl/Makefile
index 92267d6..20a943c 100644
--- a/spl/Makefile
+++ b/spl/Makefile
@@ -154,8 +154,12 @@
 $(LIBS):	depend
 	$(MAKE) -C $(SRCTREE)$(dir $(subst $(SPLTREE),,$@))
 
-$(obj)u-boot-spl.lds: $(LDSCRIPT) depend
-	$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - < $< > $@
+# The following line expands into whole rule which generates u-boot.lst,
+# the file containing u-boots LG-array linker section. This is included into
+# $(LDSCRIPT). The function make_u_boot_list is defined in helper.mk file.
+$(eval $(call make_u_boot_list, $(obj)u-boot.lst, $(LIBS)))
+$(obj)u-boot-spl.lds: $(LDSCRIPT) $(obj)u-boot.lst depend
+	$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -I$(obj). -ansi -D__ASSEMBLY__ -P - < $< > $@
 
 depend:	$(obj).depend
 .PHONY: depend