feat(plat/nxp/ls1043ardb): add ls1043ardb board support

The LS1043A reference design board (RDB) is a computing, evaluation,
and development platform that supports the Layerscape LS1043A
architecture processor.

The old implementation in tf-a (plat/layerscape/board/ls1043/) is removed,
and this patch is adding it back, it is using the unified software
component and architecture with all the other Layerscape platforms.

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Signed-off-by: Ruchika Gupta <ruchika.gupta@nxp.com>
Change-Id: I83eee2f9254267b148960b05e25b6c9ba86cf07e