feat(partition): add interface to init gpt

Current interface 'partition_init' accepts parameter image_id
and returns no value. But the entire partition driver is build
only to parse and handle GPT partitions, so add new interface
gpt_partition_init which would return failure to platform code
if it fails to parse the image.

Change-Id: Iaf574d2ad01a15d0723c1475290c31dc4a078835
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
2 files changed