common: Add .u_boot_list into all linker files

Add section for the linker-generated lists into all possible linker
files, so that everyone can easily use these lists. This is mostly
a mechanical adjustment.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
diff --git a/examples/standalone/sparc.lds b/examples/standalone/sparc.lds
index 9733daa..646b80f 100644
--- a/examples/standalone/sparc.lds
+++ b/examples/standalone/sparc.lds
@@ -46,6 +46,7 @@
 	{
 		*(.data)
 	}
+
 	. = ALIGN(4);
 	__data_end = .;