arm, am335x: Update environment variables for siemens board test mode

add variables required to boot into test mode

Signed-off-by: Pascal Bach <pascal.bach@siemens.com>
dfu, nand, ubi: add partubi alt settings for updating ubi partition

updating an ubi partition needs a completely erased mtd partition,
see:
http://lists.infradead.org/pipermail/linux-mtd/2011-May/035416.html

So, add partubi alt setting for the dfu_alt_info environment
variable to mark this partition as an ubi partition. In case we
update an ubi partition, we erase after flashing the image into the
partition, the remaining sektors.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Tom Rini <trini@ti.com>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>

***

- This patch is also a good starting point to fix up updating ubi, as
  we currently use "nand erase" for erasing the sektors. This is
  not the prefered way for writing an ubi image, see:
  http://www.linux-mtd.infradead.org/faq/ubi.html#L_flash_img

  This must be fixed ... we have no "ubiformat" in u-boot, or?
arm, am335x: siemens board update dfu_alt_info

update dfu_alt_info for the rootfs partition. As it is an ubi partition
it needs the "partubi" alt setting.

Signed-off-by: Heiko Schocher <hs@denx.de>