docs: marvell: Update build manual ...

Update build manual
- remove irrelevant platforms and environemnt variables
- add links to BLE and mv_ddr Github repositories

Change-Id: Ie389c61f014751cdc0459b3f78c70ede694d27b8
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>

docs: Add Marvell build and porting documents ...

Change-Id: I341440701b7e5e3555e604dd9d0a356795e6c4fb
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>

marvell: drivers: Add address decoding units drivers ...

Add address decoding unit drivers for Marvell SoCs.

Address decoding flow and address translation units chart
are located at docs/marvell/misc/mvebu-a8k-addr-map.txt

Change-Id: Id6ce311fa1f4f112df3adfac5d20449f495f71ed
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>