socs.d: Add support for the STMicroelectronics STiH410-B2260
The STiH410-B2260 requires us to copy an environment script for
the Primary BootLoader (PBL) to find. This has to be located in
the first partition of the SD card.
We're also providing the required simlink from boards.d.
Signed-off-by: Lee Jones <lee.jones@linaro.org>