1. Move xgmi special error inject function from amdgpu_ras.c to xgmi block.
2. Support to use psp_ras_trigger_error as default error inject function in amdgpu_ras.c. If .ras_error_inject isn't defined in ras block, default error inject function will take effect.

v2: squash in warning fix (Alex)
Signed-off-by: Nyipechai <YiPeng.Chai@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: NJohn Clements <john.clements@amd.com>
Reviewed-by: NTao Zhou <tao.zhou1@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>