drm/amd/display: add stream_enc_inst for PSP HDCP inst use

[why]
new HW engine mapping requirment use in PSP
[how]
report stream_enc_inst

Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>