Add enum definitions for soc24.

v2: Updates (Alex)
v3: Updates (Alex)
v4: Fix clash with display code (Alex)
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>