fwu: meta-data: switch to management by common code

The common code can now read, verify and fix meta-data copies
while exposing one consistent structure to users.
Only the .read_mdata() and .write_mdata() callbacks of fwu_mdata_ops
are needed. Get rid of .get_mdata() .update_mdata() .get_mdata_part_num()
.read_mdata_partition() and .write_mdata_partition() and also the
corresponding wrapper functions.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Sughosh Ganu <sughosh.ganu@linaro.org>

fwu: gpt: implement read_mdata and write_mdata callbacks

Moving towards using common code for meta-data management,
implement the read/write mdata hooks.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Sughosh Ganu <sughosh.ganu@linaro.org>

fwu: gpt: use cached meta-data partition numbers

Use cached values and avoid parsing and scanning through partitions
everytime for meta-data partitions because they can't change after bootup.

Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Sughosh Ganu <sughosh.ganu@linaro.org>

FWU: Add FWU metadata access driver for GPT partitioned block devices

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formatted with GPT based partition scheme.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

FWU: Add FWU metadata access driver for GPT partitioned block devices

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formatted with GPT based partition scheme.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>