feat(rmm): add placeholder activator callbacks for LFA

Introduce the RMM component's activator structure for use in
LFA. The 'prime' and 'activate' callbacks currently return
LFA_WRONG_STATE as placeholders.

These functions will be implemented in subsequent patches in
this series to support actual RMM component activation logic.

Change-Id: I899ff51e4065887b7b4bbfbaa827322c51cd215c
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
2 files changed