This change is in line with the project's rebranding.

The collection is also changed a bit to drop the "meta-" prefix. There
is no clear standardization on the collection name. Some use an ID, some
use ID-layer, some use meta-ID etc. We have decided to use the the layer
name without the "meta-" prefix  because this is an ID, not a layer per
se.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

x-boot - boot
x-sys-a - sys-a
x-sys-b - sys-b
x-dev-data - devdata
x-sys-data - sysdata
x-app-data - appdata

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

This makes things cleaner and more consistent when the other partitions
use variables like:
SYSDATA_PARTITION_SIZE
APPDATA_PARTITION_SIZE
etc.

Keep this change consistent on the wic files too.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

This is based on FlashLayout_sdcard_stm32mp157a-av96-extensible.tsv as a
starting point.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>