Adding labels to nodes which do not have it yet in exynos5420.
This is done so as to use reference based node updation in board
files.
Signed-off-by: Arun Kumar K <arun.kk@samsung.com> Reviewed-by: Tomasz Figa <t.figa@samsung.com> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>