barebox: Update to be able build and link with gcc6/ld.gold

Build the old barebox with newer tools. This should work for dora
and master at the same time.

recipes-bsp/barebox/barebox-sysmobts_git.bb

@@ -1,6 +1,6 @@
 require barebox.inc
 
-SRCREV = "f2b03e21a869b8df30e428ac9408d7988d55279a"
+SRCREV = "1d8bdd6f226df2ecbde3776b52fbc228158293fd"
 SRC_URI = " \
 	git://git.sysmocom.de/barebox.git;branch=v2015.06 \
 	file://defconfig \
@@ -17,6 +17,9 @@ BAREBOX_BIN_SYMLINK ?= "barebox-${MACHINE}.bin"
 # generated using echo -n 'bts-stop' | sha1sum
 BAREBOX_PASSWORD = "5a7ef8875df28cb95a0f833906f94df8573bcc5d"
 
+# Provide a replacement for calling whoami
+export KBUILD_BUILD_USER="poky"
+
 do_configure_append () {
 	mkdir -p ${WORKDIR}/env/nv
 	echo 5 > ${WORKDIR}/env/nv/login.timeout