Pull out u-boot extras into dtsi files to make synchronization of DTS
from Linux kernel as easy as a simple copy. All the U-Boot extras are
now in *-u-boot.dts* files instead.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>