arm: keep all sections in ELF file

Current LDS files /DISCARD/ a lot of sections when linking ELF
files, causing diagnostic tools such as readelf or objdump to
produce partial output. Keep all section at link stage, filter
only at objcopy time so that .bin remains minimal.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index bdabcf4..fd3e5fb 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -103,3 +103,6 @@
 # such usage by requiring word relocations.
 PLATFORM_CPPFLAGS += $(call cc-option, -mword-relocations)
 endif
+
+# limit ourselves to the sections we want in the .bin.
+OBJCFLAGS += -j .text -j .rodata -j .data -j .u_boot_list -j .rel.dyn