MLECO-2917 Replacing platform CMake definitions with headers

Moving away from CMake description of targets and generation of
platform header files (for memory addresses and IRQ numbers).
Instead these headers are part of the repository under their
respective platform-driver packages under HAL sources.

Change-Id: I9bd3e68eb17385f8b93eb3d8d76b212ce0e1a6d5
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>