Add GPT based partition configurator

Adds the capability to configure a partitioned_block_store from
a GUID partition table read from the backend storage device. The
block_storage standalone service context (used in PC based testing)
has been modified to use GPT based configuration using the
reference disk image that defines a set of partitions expected by
test cases.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: Idcb677c348468bcd5e435aa3ef72750ca8ccbf38
13 files changed