refactor(gpt): return header instead of part_lba

Alter the function parameter to pass the full GPT header to be filled
instead of the starting LBA of the array of partion entries to
load_partition_gpt()

Change-Id: Ib3dde62d5b9996e74157714634bea748bd3b55aa
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
1 file changed