feat(cpu): add library support for Hunter ELP

Add basic CPU library code to support the Hunter ELP CPU in TF-A.
Hunter-ELP adds v9.2 architecture support and is derived from
Makalu-ELP. As such, the library code is adapted from the
Makalu-ELP support library.

Change-Id: I7e93b9af6b1f0bc4d08c3cf5caf071d2cbdbc89f
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
4 files changed