Add tct/flash/flash_dd.sh script

Add tct/flash/flash_dd.sh script

It flashes SD card with images available in a directory it is
invoked in using dd. For more information read file header.

SD card should be prepared using script mkpart.sh available at:
https://wiki.tizen.org/wiki/Quick_guide_for_odroid#Fuse_bootloader_image

Example: ./flash_dd.sh /dev/sdb
Flashes as follows:
    * boot.img to /dev/sdb1
    * rootfs.img to /dev/sdb2
    * system-data.img to /dev/sdb3
    * user.img to /dev/sdb5
    * modules.img to /dev/sdb6

Change-Id: I2d5b72cf4d2079632cbd700dd5749260782868b8
Signed-off-by: Aleksander Mistewicz <a.mistewicz@samsung.com>