plat: marvell: armada: platform definitions cleanup

plat: marvell: armada: platform definitions cleanup

- Remove
    TRUSTED_DRAM_BASE
    TRUSTED_DRAM_SIZE
    MARVELL_TRUSTED_SRAM_BASE
- Rename
    PLAT_MARVELL_TRUSTED_DRAM_* -> PLAT_MARVELL_TRUSTED_RAM_*
    PLAT_MARVELL_TRUSTED_SRAM_* -> MARVELL_TRUSTED_DRAM_*
    MARVELL_MAP_SHARED_RAM -> MARVELL_MAP_SECURE_RAM
- Move
    MARVELL_TRUSTED_DRAM_SIZE to marvell_def.h
- Enable MARVELL_MAP_SECURE_RAM region in BL2U memory map
- Add dependency of MARVELL_MAP_SHARED_RAM on LLC_SRAM
- Add minor style improvents

Change-Id: Iebc03361e4f88489af1597f54e137b27c241814c
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
[Improve patch after rebase]
Signed-off-by: Marcin Wojtas <mw@semihalf.com>