Davinci boards tend to have older booloaders without DTB support.
Enable appended DTB support by default to allow DT booting on older
platforms.  While there, also enable /proc/device-tree support for
easy verification of DT boot.
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>