refactor(neoverse-rd): remove unused defines from platform_def.h

As part of the refactoring for A75/V1/N1 CPU based platforms, remove
unused defines from the platform_def.h for each of these platforms.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: I37a6d82ad2f80a5c92b2652432fe2d211e052580
4 files changed