refactor(arm): use gpt_partition_init

Current interface partition_init accepts GPT image id and parses the
GPT image but doesn't return any error on failure.

So use gpt_partition_init which implicitly initialises with GPT image
ID and returns a value.

Change-Id: I63280aa672388f1f8d9dc377ae13002c9f861f03
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
1 file changed