Add recipes for TF-A versions 2.2 and 2.3

Add basic recipes for TF-A versions 2.2 and 2.3.  Also, rearrange fields
in the various TF-A recipes to make them uniform and move the
do_compile_prepend to the inc file.

Change-Id: I85e4ac7bdc44ed85449e40fd2c94d73bf3e7d9e8
Signed-off-by: Jon Mason <jon.mason@arm.com>
Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>