build: link with --build-id=none

Some toolchains are compiled so that they pass a --build-id=something
parameter to the linker implicitly.

This causes U-Boot LTO linking to fail with something like:
  ld: section .note.gnu.build-id LMA ... overlaps section .text LMA ...
because U-Boot's link scripts do not currently handle .note.gnu.build-id
section.

Fix this by explicitly disabling build-id.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/Makefile b/Makefile
index d2fdac7..a038c6d 100644
--- a/Makefile
+++ b/Makefile
@@ -997,6 +997,8 @@
 # Avoid 'Not enough room for program headers' error on binutils 2.28 onwards.
 LDFLAGS_u-boot += $(call ld-option, --no-dynamic-linker)
 
+LDFLAGS_u-boot += --build-id=none
+
 ifeq ($(CONFIG_ARC)$(CONFIG_NIOS2)$(CONFIG_X86)$(CONFIG_XTENSA),)
 LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)
 endif