This commit adds common dtsi for the following Sercomm devices with 256
MB NAND:
Beeline Smartbox TURBO (Sercomm DF3)
Rostelecom RT-SF-1 (Sercomm DKG)
Also fixed typo ("Container" mtd name should be with a capital).
Signed-off-by: Mikhail Zhilkin <csharper2005@gmail.com>
