sgi: sgm: Migrate to new interfaces

- Remove references to removed build options.
- Remove support for LOAD_IMAGE_V2=0.

Change-Id: I296385ef2ebf829446c76a54400d73f963ed265f
Tested-by: Nariman Poushin <nariman.poushin@linaro.org>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
8 files changed