drm/amd: consolidate TA shared memory structures

drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c

drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h

drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c

drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c

drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c